Automated analysis of multiple-input, multiple-output (mimo) communications stream distribution to remote units in a distributed communication system (dcs) to support configuration of interleaved mimo communications services

ABSTRACT

Distributed communications systems (DCSs) supporting automated analysis of MIMO communications stream distribution to remote units in a distributed communication system (DCS) to support configuration of interleaved MIMO communications services are disclosed. In this regard, MIMO analysis circuits can be employed to determine the actual routing of MIMO communications signals and locations of the remote units to automatedly determine any MIMO cell bonding between the remote units to determine the configured interleaved MIMO configuration in effect in the DCS. The determined interleaved MIMO configuration of the DCS infrastructure is used to determine other possible interleaved MIMO configurations and their associated performance, along with the associated configurations and changes needed to realize such possible interleaved MIMO configurations. These possible interleaved MIMO communications service configurations can then be presented to a technician or customer to determine if any of the possible interleaved MIMO communication service configurations should be deployed in the DCS.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of priority under 35 U.S.C. § 119 ofU.S. Provisional Application No. 62/513,051 filed on May 31, 2017 andProvisional Application No. 62/513,045 filed on May 31, 2017, thecontent of which are relied upon and incorporated herein by reference intheir entireties.

BACKGROUND

The disclosure relates generally to distributed communications systems(DCSs), such as distributed antenna systems (DAS) for example, capableof distributing wireless radio-frequency (RF) communications servicesover wired communications mediums to remote units to provide remotecommunications coverage areas for distributing the RF communicationsservices to wireless client devices.

Wireless customers are increasingly demanding wireless communicationsservices, such as cellular communications services and Wi-Fi services.Thus, small cells, and more recently Wi-Fi services, are being deployedindoors. At the same time, some wireless customers use their wirelesscommunication devices in areas that are poorly serviced by conventionalcellular networks, such as inside certain buildings or areas where thereis little cellular coverage. One response to the intersection of thesetwo concerns has been the use of wireless distributed communicationssystems (DCSs), such as distributed antenna systems (DASs). DASs includeremote antenna units (RAUs) configured to receive and transmitcommunications signals to client devices within the antenna range of theRAUs. DASs can be particularly useful when deployed inside buildings orother indoor environments where the wireless communication devices maynot otherwise be able to effectively receive radio frequency (RF)signals from a source.

In this regard, FIG. 1 illustrates a wireless DCS 100 that is configuredto distribute communications services to remote coverage areas102(1)-102(N), where ‘N’ is the number of remote coverage areas. Thewireless DCS 100 in FIG. 1 is provided in the form of a DAS 104. The DAS104 can be configured to support a variety of communications servicesthat can include cellular communications services, wirelesscommunications services, such as RF identification (RFID) tracking,Wireless Fidelity (Wi-Fi), local area network (LAN), and wireless LAN(WLAN), wireless solutions (Bluetooth, Wi-Fi Global Positioning System(GPS) signal-based, and others) for location-based services, andcombinations thereof, as examples. The remote coverage areas102(1)-102(N) are created by and centered on remote units 106(1)-106(N)communicatively coupled to a central unit 108 (e.g., a head-endcontroller, a central unit, or a head-end unit). The central unit 108may be communicatively coupled to a source transceiver 110, such as forexample, a base transceiver station (BTS) or a baseband unit (BBU). Inthis regard, the central unit 108 receives downlink communicationssignals 112D from the source transceiver 110 to be distributed to theremote units 106(1)-106(N). The downlink communications signals 112D caninclude data communications signals and/or communication signalingsignals, as examples. The central unit 108 is configured with filteringcircuits and/or other signal processing circuits that are configured tosupport a specific number of communications services in a particularfrequency bandwidth (i.e., frequency communications bands). The downlinkcommunications signals 112D are communicated by the central unit 108over a communications link 114 over their frequency to the remote units106(1)-106(N).

With continuing reference to FIG. 1, the remote units 106(1)-106(N) areconfigured to receive the downlink communications signals 112D from thecentral unit 108 over respective communications links 114(1)-114(N). Thedownlink communications signals 112D are configured to be distributed tothe respective remote coverage areas 102(1)-102(N) of the remote units106(1)-106(N). The remote units 106(1)-106(N) are also configured withfilters and other signal processing circuits that are configured tosupport all or a subset of the specific communications services (i.e.,frequency communications bands) supported by the central unit 108. In anon-limiting example, the communications links 114(1)-114(N) may be awired communications link, a wireless communications link, or an opticalfiber-based communications link. Each of the remote units 106(1)-106(N)may include an RF transmitter/receiver 116(1)-116(N) and a respectiveantenna 118(1)-118(N) operably connected to the RF transmitter/receiver116(1)-116(N) to wirelessly distribute the communications services to awireless client device 120 within the respective remote coverage areas102(1)-102(N). The remote units 106(1)-106(N) are also configured toreceive uplink communications signals 112U from the wireless clientdevice 120 in the respective remote coverage areas 102(1)-102(N) to bedistributed to the source transceiver 110.

One problem that can exist with wireless communication systems,including the system 100 in FIG. 1, is the multi-path (fading) nature ofsignal propagation. This simply means that local maxima and minima ofdesired signals can exist over a picocell coverage area. A receiverantenna located at a maximum location will have better performance orsignal-to-noise ratio (SNR) than a receiver antenna located in a minimumposition. Signal processing techniques can be employed to improve theSNR of wireless data transmission in such wireless communicationsystems. For example, spatial diversity can be utilized in instancesinvolving many access points. Other signal processing techniques includemultiple-input, multiple-output (MIMO) techniques for increasing bitrates or beam forming for SNR, or wireless distance improvement. MIMO isthe use of multiple antennas at both a transmitter and receiver toincrease data throughput and link range without additional bandwidth orincreased transmit power. MIMO technology can be employed in DASs toincrease the bandwidth up to twice the nominal bandwidth.

Even with the potential doubling of bandwidth in a DCS employing MIMOtechnology, a client device must still be within range of two MIMOantennas to realize the full benefits of increased bandwidth of MIMOtechnology. Ensuring uniform MIMO coverage may be particularly importantfor newer cellular standards, such as Long Term Evolution (LTE), whereincreased bandwidth requirements are expected by users of client devicesin all coverage areas.

MIMO communications services require at least two (2) communicationsstreams being distributed in a given coverage area. For example, toprovide MIMO communications services in the DAS 104 in FIG. 1, remoteunits 106(1)-106(N) in the DAS 104 can be co-located. For example, FIG.2 illustrates the DAS 104 in FIG. 1 with co-located remote units 106(1),106(2) and co-located remote units 106(3), 106(4). The co-located remoteunits 106(1), 106(2) are separated a distance D₁ from the otherco-located remote units 106(3), 106(4) such that two distinct MIMOcoverage areas 204(1), 204(2) are formed by the respective co-locatedremote units 106(1), 106(2) and co-located remote units 106(3), 106(4).Each remote unit 106(1)-106(4) has a respective radio 202(1)-202(4)configured to distribute a communication stream including one or morecommunications bands. Each radio 202(1)-202(4) may be configured tosupport the same communications bands, or a common subset ofcommunications bands. Co-located remote units 106(1), 106(2) provide thefirst MIMO coverage area 204(1) by respectively receiving anddistributing MIMO communications streams 200(1), 200(2). Co-locatedremote units 106(3), 106(4) provide the second MIMO coverage area 204(2)by also respectively receiving and distributing MIMO communicationsstreams 200(1), 200(2). As shown in FIG. 2, a wireless client device 120located within the first MIMO coverage area 204(1) will receive the MIMOcommunications streams 200(1), 200(2) for a MIMO communications servicefrom the co-located remote units 106(1), 106(2), because the wirelessclient device 120 will be in communications range of both remote units106(1), 106(2). Similarly, if the wireless client device 120 werelocated in the second MIMO coverage area 204(2) in range of both remoteunits 106(3), 106(4), the wireless client device 120 would receive MIMOcommunications streams 200(1), 200(2) for a MIMO communications servicethrough remote units 106(3), 106(4). If however, the wireless clientdevice 120 were located in a coverage area outside or on the edge of thefirst and second MIMO coverage areas 204(1), 204(2), the wireless clientdevice 120 may still be in communication range of at least one of theremote units 106(1)-106(4) to receive one of the MIMO communicationsstreams 200(1) or 200(2). However, the wireless client device 120 maynot be in communication range with sufficient signal-to-noise (SNR)ratio of another remote unit 106(1)-106(4), to receive the other MIMOcommunications streams 200(2) or 200(1). Thus, in this example, thewireless client device 120 would only receive single input, singleoutput (SISO) communications services in the DAS 104.

Providing co-located remote units 106(1)-106(N) in the DAS 104 canincrease the MIMO coverage areas 204 provided in the DAS 104 to reduceor eliminate non-MIMO coverage areas where only SISO communicationsservices are available. However, providing co-located remote units106(1)-106(N) increases the number of remote units 106(1)-106(N) in theDAS 104 for the number of MIMO coverage areas 204 provided. For example,as shown in FIG. 2, two (2) remote units 106(1), 106(2) are required tobe co-located to form the single MIMO coverage area 204(1). If a 4×4MIMO communications service is desired, then four (4) remote units106(1)-106(N) would be required to be co-located to form a single MIMOcoverage area 204. Providing an increased number of remote units106(1)-106(N) to provide MIMO communications services in the DAS 104adds complexity and associated cost by requiring support of a greaternumber of remote units 106(1)-106(N) to as well as increased costsassociated with providing additional communications links 114(1)-114(N)for each MIMO coverage area 204.

No admission is made that any reference cited herein constitutes priorart. Applicant expressly reserves the right to challenge the accuracyand pertinency of any cited documents.

SUMMARY

Embodiments disclosed herein include automated analysis ofmultiple-input, multiple-output (MIMO) communications streamdistribution to remote units in a distributed communication system (DCS)to support configuration of interleaved MIMO communications services.MIMO communication services involve use of multiple antennas at both atransmitter and receiver to increase data throughput and link range toincrease bandwidth up to twice nominal bandwidth. Related circuits,systems, and methods are also disclosed. In this regard, in exemplaryaspects disclosed herein, DCSs are disclosed that are capable ofdistributing MIMO communications streams for a MIMO communicationsservice in remote coverage areas between remote units and client devicesin wireless communication range of remote units. The DCS can beconfigured to distribute a separate MIMO communications stream to eachof multiple remote units, which in turn distribute the received MIMOcommunications stream in a remote MIMO coverage area to provide MIMOcommunications services to client devices in the remote coverage area.In this regard, an antenna of each remote unit radiates a respectivereceived downlink MIMO communications stream received from the centralunit in the overlapping MIMO coverage area. An antenna of each remoteunit also receives a respective uplink MIMO communications streamreceived from a client device in the overlapping MIMO coverage area.

The remote units in the DCS configured to distribute MIMO communicationsstreams for a MIMO communications service can be co-located with eachother such that the remote coverage areas of each remote unitsubstantially overlap to form a remote MIMO coverage area. However, thisrequires providing multiple remote units for each desired remote MIMOcoverage area, thereby increasing costs and complexity. In this regard,in aspects disclosed herein, to reduce the number of remote units in theDCS while still providing the desired remote MIMO coverage areas, theDCSs disclosed herein can be configured to provide interleaved MIMOcommunications services. Interleaved MIMO communications servicesinvolves configuring multiple adjacent remote units separated by aprescribed distance in the DCS and having respective, adjacent,substantially non-overlapping remote coverage areas to each receive aMIMO communications stream for a MIMO communications service to form aremote MIMO coverage area. By the multiple adjacent remote units beinglocated at a prescribed distance from each other, each of theirrespective antennas are in essence “bonded” together through theirdistribution and reception of separate MIMO communications streams inthe remote MIMO coverage area to form interleaved MIMO cell bondedremote units. The size of the remote MIMO coverage area formed by theinterleaved MIMO cell bonded remote units is a function of the distancebetween the interleaved MIMO cell bonded remote units, because thisdistance affects the signal quality level required by a client device toreceive the MIMO communications streams from each of the interleavedMIMO cell bonded remote units. If a client device does not haveacceptable and/or higher communications signal quality with an antennaof a single remote unit, the client device will engage in MIMOcommunications through the interleaved MIMO cell bonded remote units. Ifhowever, a client device has acceptable and/or higher communicationssignal quality with a subset of the antennas of the interleaved MIMOcell bonded remote units, the client device will engage in single-input,single-output (SISO) communications through a remote unit of theinterleaved MIMO cell bonded remote units. More sparse and lower costremote unit deployments can thus provide substantially uniformhigh-capacity MIMO DAS coverage.

In aspects disclosed herein, to provide the desired interleaved MIMOcommunications services, the DCS supports automated analysis of MIMOcommunications stream distribution to remote units in a DCS to supportconfiguration of interleaved MIMO communications services. MIMO analysiscircuits can be employed to determine the actual routing of MIMOcommunications signals and locations of the remote units to automatedlydetermine any MIMO cell bonding between the remote units to determinethe interleaved MIMO configuration in effect in the DCS, if any. Thedetermined interleaved MIMO configuration of the existing DCSinfrastructure is used to determine other possible interleaved MIMOconfigurations in the DCS and their associated performance, along withthe associated configurations and changes needed to realize suchpossible interleaved MIMO configurations. As one option, the changes andoptimizations required to realize the possible interleaved MIMOconfigurations may be determined based on using a radio frequency (RF)simulation software program, if available, to create a “heat” map ofboth SISO and interleaved MIMO remote coverage areas of the remote unitsfor the possible interleaved MIMO configurations. These possibleinterleaved MIMO communications service configurations can then bepresented to a technician or customer to determine if any of thepossible interleaved MIMO communications service configurations shouldbe deployed in the DCS. For example, one possible interleaved MIMOcommunications service configuration may be to change the MIMOcommunications services supported by a DCS from 2×2 interleaved MIMOcommunications services to 4×4 interleaved MIMO communications services.If the possible interleaved MIMO communications service configurationsshould be deployed in the DCS, the DCS can be reconfigured to supportthe selected interleaved MIMO communications service configurations. Inthis manner, interleaved MIMO communications services can be configuredfor a DCS using an existing infrastructure of remote units havingsubstantially non-overlapping remote coverage areas, by directing theMIMO communications streams over the configured physical layers to beprovided to the desired remote units to facilitate interleaved MIMO cellbonding of remote units.

If the infrastructure of the DCS is indicated as not being able to bechanged, the possible interleaved MIMO communications serviceconfigurations presented will involve using the existing infrastructureof remote units and their locations, but with possible differentphysical layer assignments for distribution of MIMO communicationsstreams to the remote units. If the infrastructure of the DCS isindicated as being able to be changed, the possible interleaved MIMOcommunications service configurations presented can also involvechanging (e.g., adding to) the number and/or location of remote unitsalong with possible different physical layer assignments fordistribution of MIMO communications streams to the remote units.

In this regard, in one exemplary aspect, distributed communicationssystem (DCS) is disclosed. The DCS comprises a central unit. The centralunit is configured to distribute received one or more downlinkcommunications signals over one or more downlink communications linksamong a plurality of downlink communications links to one or more remoteunits among a plurality of remote units according to a routingconfiguration and distribute received one or more uplink communicationssignals from the plurality of remote units over a plurality of uplinkcommunications links. The central unit comprises a routing configurationassigning received one or more downlink communications signals to one ormore remote units among the plurality of remote units and a centralmultiple-input, multiple-output (MIMO) analysis circuit configured todetermine the presence of MIMO communications signals among the receivedone or more downlink communications signals. Each remote unit among theplurality of remote units comprises at least one antenna and isconfigured to distribute received uplink communications signals receivedover the at least one antenna over an uplink communications link amongthe plurality of uplink communications links to the central unit anddistribute received downlink communications signals from a downlinkcommunications link among the plurality of downlink communications linksthrough the at least one antenna. Each remote unit among the pluralityof remote units further comprising a remote MIMO analysis circuit isconfigured to determine the presence of MIMO communications signalsamong the received downlink communications signals, determine locationof the remote unit, and provide MIMO analysis information comprising thepresence of MIMO communications signals and the determined location ofthe remote unit. The central unit further comprises a controllerconfigured to instruct the central MIMO analysis circuit to analyze thereceived one or more downlink communications signals to determine thepresence of MIMO communications signals. The controller is alsoconfigured to instruct the plurality of remote units to cause theirrespective remote MIMO analysis circuit to analyze the received one ormore downlink communications signals to determine the presence of MIMOcommunications signals. The controller is also configured to determine arouting configuration of the determined MIMO communications signalsamong the one or more downlink communications signals from the centralunit to the plurality of remote units. The controller is also configuredto receive MIMO analysis information from each remote unit among theplurality of remote units indicating the determined presence of MIMOcommunications signals and the location of the remote unit. In responseto the determined presence of MIMO communications signals from thereceived MIMO analysis information the controller is configured todetermine at least one interleaved MIMO configuration for the routingconfiguration based on the received MIMO analysis information; andconfigure the routing configuration based on the determined at least oneinterleaved MIMO configuration. The controller is also configured toassign a first MIMO communications signal among the received one or moredownlink communications signals for a first MIMO communications serviceto a first remote unit among the plurality of remote units having afirst remote coverage area and assign a second MIMO communicationssignal among the received one or more downlink communications signalsfor the first MIMO communications service to a second remote unit amongthe plurality of remote units having a second remote coverage areaoverlapping with the first remote coverage area to interleave MIMO cellbond the first remote unit and the second remote unit.

An additional aspect of the disclosure relates to method of configuringa distributed communications systems (DCS) for providing interleavedmultiple-input, multiple-output (MIMO) communications services. Themethod comprises instructing a central MIMO analysis circuit in acentral unit of a DCS to analyze received at least one downlinkcommunications signals to determine a presence of MIMO communicationssignals. The DCS comprises the central unit configured to distributereceived one or more downlink communications signals over one or moredownlink communications links among a plurality of downlinkcommunications links to one or more remote units among a plurality ofremote units according to a routing configuration. The central unit isalso comprised to distribute received one or more uplink communicationssignals from the plurality of remote units over a plurality of uplinkcommunications links. The central unit comprises a routing configurationassigning received one or more downlink communications signals to one ormore remote units among the plurality of remote units and a central MIMOanalysis circuit configured to determine the presence of MIMOcommunications signals among the received one or more downlinkcommunications signals. Each remote unit among the plurality of remoteunits comprises at least one antenna and is configured to distributereceived uplink communications signals over the at least one antennaover an uplink communications link among the plurality of uplinkcommunications links to the central unit, and distribute receiveddownlink communications signals from a downlink communications linkamong the plurality of downlink communications links through the atleast one antenna. Each remote unit among the plurality of remote unitsfurther comprises a remote MIMO analysis circuit is configured todetermine the presence of MIMO communications signals among the receiveddownlink communications signals, determine location of the remote unit,and provide MIMO analysis information comprising the presence of MIMOcommunications signals and the determined location of the remote unit.The method further comprises instructing the plurality of remote unitsto cause their respective remote MIMO analysis circuit to analyze thereceived one or more downlink communications signals to determine thepresence of MIMO communications signals. The method further comprisesdetermining a routing configuration of the determined MIMOcommunications signals among the received one or more downlinkcommunications signals from the central unit to the plurality of remoteunits. The method further comprises receiving MIMO analysis informationfrom each remote unit among the plurality of remote units indicating thedetermined presence of MIMO communications signals and the location ofthe remote unit. In response to the determined presence of MIMOcommunications signals from the received MIMO analysis information, themethod further comprises determining at least one interleaved MIMOconfiguration for the routing configuration based on the received MIMOanalysis information and configuring the routing configuration based onthe determined at least one interleaved MIMO configuration by assigninga first MIMO communications signal among the received one or moredownlink communications signals for a first MIMO communications serviceto a first remote unit among the plurality of remote units having afirst remote coverage area and assigning a second MIMO communicationssignal among the received one or more downlink communications signalsfor the first MIMO communications service to a second remote unit amongthe plurality of remote units having a second remote coverage areaoverlapping with the first remote coverage area to interleave MIMO cellbond the first remote unit and the second remote unit.

An additional aspect of the disclosure relates to a non-transitorycomputer-readable medium having stored thereon computer executableinstructions which, when executed by a processor, cause the processor toinstruct a central multiple-input, multiple-output (MIMO) analysiscircuit in a central unit of a distributed communications system (DCS)to analyze received at least one downlink communications signals todetermine a presence of MIMO communications signals. The DCS comprises acentral unit. The central unit is configured to distribute received oneor more downlink communications signals over one or more downlinkcommunications links among a plurality of downlink communications linksto one or more remote units among a plurality of remote units accordingto a routing configuration, and distribute received one or more uplinkcommunications signals from the plurality of remote units over aplurality of uplink communications links. The central unit comprises arouting configuration assigning received one or more downlinkcommunications signals to one or more remote units among the pluralityof remote units and the central MIMO analysis circuit configured todetermine the presence of MIMO communications signals among the receivedone or more downlink communications signals. Each remote unit among theplurality of remote units comprises at least one antenna and isconfigured to distribute received uplink communications signals over theat least one antenna over an uplink communications link among theplurality of uplink communications links to the central unit anddistribute received downlink communications signals from a downlinkcommunications link among the plurality of downlink communications linksthrough the at least one antenna. Each remote unit among the pluralityof remote units further comprises a remote MIMO analysis circuitconfigured to determine the presence of MIMO communications signalsamong the received downlink communications signals, determine locationof the remote unit, and provide MIMO analysis information comprising thepresence of MIMO communications signals and the determined location ofthe remote unit. The processor also instructs the plurality of remoteunits to cause their respective remote MIMO analysis circuit to analyzethe received one or more downlink communications signals to determinethe presence of MIMO communications signals. The processor alsodetermines a routing configuration of the determined MIMO communicationssignals among the received one or more downlink communications signalsfrom the central unit to the plurality of remote units. The processoralso receives MIMO analysis information from each remote unit among theplurality of remote units indicating the determined presence of MIMOcommunications signals and the location of the remote unit. In responseto the determined presence of MIMO communications signals from thereceived MIMO analysis information, the processor determines at leastone interleaved MIMO configuration for the routing configuration basedon the received MIMO analysis information, and configures the routingconfiguration based on the determined at least one interleaved MIMOconfiguration. The processor also assigns a first MIMO communicationssignal among the received one or more downlink communications signalsfor a first MIMO communications service to a first remote unit among theplurality of remote units having a first remote coverage area, andassigns a second MIMO communications signal among the received one ormore downlink communications signals for the first MIMO communicationsservice to a second remote unit among the plurality of remote unitshaving a second remote coverage area overlapping with the first remotecoverage area to interleave MIMO cell bond the first remote unit and thesecond remote unit.

Additional features and advantages will be set forth in the detaileddescription which follows and, in part, will be readily apparent tothose skilled in the art from the description or recognized bypracticing the embodiments as described in the written description andclaims hereof, as well as the appended drawings.

It is to be understood that both the foregoing general description andthe following detailed description are merely exemplary and are intendedto provide an overview or framework to understand the nature andcharacter of the claims.

The accompanying drawings are included to provide a furtherunderstanding of the disclosure, and are incorporated in and constitutea part of this specification. The drawings illustrate one or moreembodiment(s), and together with the description serve to explainprinciples and operation of the various embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of an exemplary wireless distributedcommunications system (DCS) in the form of a distributed antenna system(DAS);

FIG. 2 is schematic diagram of two MIMO coverage areas formed in the DASof FIG. 1 by respective co-located remote units;

FIG. 3 is a schematic diagram of an exemplary optical fiber-based DCS inthe form of a DAS configured to distribute communications signalsbetween a central unit and a plurality of remote units, and that caninclude one or more power distribution systems configured to distributepower to a plurality of remote units and provide a safety powerdisconnect of the power source to remote units;

FIG. 4A is a partially schematic cut-away diagram of an exemplarybuilding infrastructure in which a DCS in FIG. 3 can be provided;

FIG. 4B is a more detailed schematic diagram of the DCS in FIG. 4A;

FIG. 5A is a schematic diagram of a DCS configured to support co-locatedMIMO communications services with client devices;

FIG. 5B is a schematic of a downlink path and uplink path and relatedcomponents of the remote unit in the DCS of FIG. 5A;

FIG. 6 is a schematic diagram of exemplary adjacent remote units in aDCS, such as the DCS in FIGS. 5A and 5B, having exemplary substantiallynon-overlapping remote coverage areas and located a defined distancefrom each other to be capable of being interleaved MIMO cell bondedtogether to support interleaved MIMO communications services;

FIG. 7 is a schematic diagram of exemplary adjacent remote units in aDCS, such as the DCS in FIGS. 5A and 5B, located a defined distance fromeach other to show both traditional and interleaved MIMO cell bonding tosupport both SISO and interleaved MIMO communications services;

FIG. 8 is a graph illustrating an exemplary percentage of remotecoverage area of the remote units in FIG. 7 supporting MIMOcommunications services as a function of distance between the remoteunits for both traditional and interleaved MIMO cell bonding;

FIGS. 9A-9C are schematic diagrams illustrating different, exemplarySISO, 2×2, and 4×4 interleaved MIMO cell bonding configurations that canbe configured and/or re-configured in the DCS in FIG. 5A based onconfiguring and/or re-configuring the distribution of MIMOcommunications streams to designated remote units in the DCS;

FIG. 10A is a schematic diagrams illustrating the DCS in FIGS. 5A and 5Bconfigured to support distribution of SISO communications streams toremote units to support SISO communication services;

FIG. 10B is a schematic diagram of a building layout employing the DCSin FIG. 10A configured to support distribution of SISO communicationsstreams to remote units to support SISO communication services;

FIG. 11A is a schematic diagram illustrating the DCS in FIG. 10Are-configured to support interleaved distribution of MIMO communicationsstreams to remote units to provide 2×2 interleaved MIMO communicationservices;

FIGS. 11B and 11C are schematic diagrams of exemplary building layoutsemploying the DCS in FIG. 11A configured to support interleaveddistribution of MIMO communications streams to remote units to provide2×2 interleaved MIMO communication services;

FIG. 12 is a schematic diagram illustrating the DCS in FIG. 11Are-configured to support interleaved distribution of MIMO communicationsstreams to remote units to provide 4×4 interleaved MIMO communicationservices;

FIG. 13 is a flowchart illustrating an exemplary process of configuringand/or re-configuring the DCS in FIGS. 5A and 5B to support interleavedMIMO communications services based on the existing remote units deployedin the DCS and their installed locations to achieve a desiredinterleaved MIMO communications services performance in the DCS;

FIG. 14 is a flowchart illustrating an exemplary process of configuringand/or re-configuring the DCS in FIGS. 5A and 5B to support interleavedMIMO communications services based on the existing remote units deployedin the DCS and with repositioning installed locations of remote unitsand/or adding MIMO communications streams to achieve a desiredinterleaved MIMO communications services performance in the DCS;

FIGS. 15A and 15B are schematic diagrams of the DCS in FIGS. 5A and 5Bwith additional MIMO analysis circuits employed in the head-end unit todetermine the actual routing of MIMO communications signals andlocations of the remote units in the DCS to allow for automatedlydetermining any MIMO cell bonding between the remote units to determinethe configuration interleaved MIMO configuration in effect in the DCS;

FIG. 16 is a schematic diagram of exemplary components that can beincluded in the MIMO analysis circuit in FIGS. 15A and 15B;

FIG. 17 is a flowchart illustrating an exemplary process of automatedlydetermining the actual routing of MIMO communications signals andlocations of the remote units in the DCS and any MIMO cell bondingbetween the remote units to determine the configured interleaved MIMOconfiguration in effect in the DCS, and re-configuring the DCS toprovide the desired interleaved MIMO configuration in response to thedetermined interleaved MIMO configuration in the DCS;

FIG. 18 is a flowchart illustrating an exemplary process of routing ofMIMO communications signals and locations of the remote units in theDCS, automatedly determining any MIMO cell bonding between the remoteunits to determine the configured interleaved MIMO configuration ineffect in the DCS, and re-configuring the DCS to provide the desiredinterleaved MIMO configuration;

FIGS. 19A and 19B are diagrams of exemplary graphical user interfaces(GUI) that facilitate configuring and/or reconfiguring distribution ofMIMO communications streams in a DCS, such as the DCS in FIGS. 15A and15B and according to any of the exemplary interleaved MIMOcommunications services discussed herein, displayed on a display in acomputer system in response to a processor executing of softwareinstructions; and

FIG. 20 is a schematic diagram of an exemplary computer system that canbe included in any component in a DCS, including but not limited to theDCS in FIGS. 15A and 15B, wherein the computer system includes aprocessor that is configured to software execute instructions to supportconfiguring and/or reconfiguring distribution of MIMO communicationsstreams in a DCS, such as the DCS in FIGS. 15A and 15B.

DETAILED DESCRIPTION

Embodiments disclosed herein include automated analysis ofmultiple-input, multiple-output (MIMO) communications streamdistribution to remote units in a distributed communication system (DCS)to support configuration of interleaved MIMO communications services.MIMO communication services involve use of multiple antennas at both atransmitter and receiver to increase data throughput and link range toincrease bandwidth up to twice nominal bandwidth. Related circuits,systems, and methods are also disclosed. In this regard, in exemplaryaspects disclosed herein, DCSs are disclosed that are capable ofdistributing MIMO communications streams for a MIMO communicationsservice in remote coverage areas between remote units and client devicesin wireless communication range of remote units. The DCS can beconfigured to distribute a separate MIMO communications stream to eachof multiple remote units, which in turn distribute the received MIMOcommunications stream in a remote MIMO coverage area to provide MIMOcommunications services to client devices in the remote coverage area.In this regard, an antenna of each remote unit radiates a respectivereceived downlink MIMO communications stream received from the centralunit in the overlapping MIMO coverage area. An antenna of each remoteunit also receives a respective uplink MIMO communications streamreceived from a client device in the overlapping MIMO coverage area.

The remote units in the DCS configured to distribute MIMO communicationsstreams for a MIMO communications service can be co-located with eachother such that the remote coverage areas of each remote unitsubstantially overlap to form a remote MIMO coverage area. However, thisrequires providing multiple remote units for each desired remote MIMOcoverage area, thereby increasing costs and complexity. In this regard,in aspects disclosed herein, to reduce the number of remote units in theDCS while still providing the desired remote MIMO coverage areas, theDCSs disclosed herein can be configured to provide interleaved MIMOcommunications services. Interleaved MIMO communications servicesinvolves configuring multiple adjacent remote units separated by aprescribed distance in the DCS and having respective, adjacent,substantially non-overlapping remote coverage areas to each receive aMIMO communications stream for a MIMO communications service to form aremote MIMO coverage area. By the multiple adjacent remote units beinglocated at a prescribed distance from each other, each of theirrespective antennas are in essence “bonded” together through theirdistribution and reception of separate MIMO communications streams inthe remote MIMO coverage area to form interleaved MIMO cell bondedremote units. The size of the remote MIMO coverage area formed by theinterleaved MIMO cell bonded remote units is a function of the distancebetween the interleaved MIMO cell bonded remote units, because thisdistance affects the signal quality level required by a client device toreceive the MIMO communications streams from each of the interleavedMIMO cell bonded remote units. If a client device does not haveacceptable and/or higher communications signal quality with an antennaof a single remote unit, the client device will engage in MIMOcommunications through the interleaved MIMO cell bonded remote units. Ifhowever, a client device has acceptable and/or higher communicationssignal quality with a subset of the antennas of the interleaved MIMOcell bonded remote units, the client device will engage in single-input,single-output (SISO) communications through a remote unit of theinterleaved MIMO cell bonded remote units. More sparse and lower costremote unit deployments can thus provide substantially uniformhigh-capacity MIMO DAS coverage.

In aspects disclosed herein, to provide the desired interleaved MIMOcommunications services, the DCS supports automated analysis of MIMOcommunications stream distribution to remote units in a DCS to supportconfiguration of interleaved MIMO communications services. MIMO analysiscircuits can be employed to determine the actual routing of MIMOcommunications signals and locations of the remote units to automatedlydetermine any MIMO cell bonding between the remote units to determinethe configured interleaved MIMO configuration in effect in the DCS, ifany. The determined interleaved MIMO configuration of the existing DCSinfrastructure is used to determine other possible interleaved MIMOconfigurations in the DCS and their associated performance, along withthe associated configurations and changes needed to realize suchpossible interleaved MIMO configurations. As one option, the changes andoptimizations required to realize the possible interleaved MIMOconfigurations may be determined based on using a radio frequency (RF)simulation software program, if available, to create a “heat” map ofboth SISO and interleaved MIMO remote coverage areas of the remote unitsfor the possible interleaved MIMO configurations. These possibleinterleaved MIMO communications service configurations can then bepresented to a technician or customer to determine if any of thepossible interleaved MIMO communications service configurations shouldbe deployed in the DCS. For example, one possible interleaved MIMOcommunications service configuration may be to change the MIMOcommunications services supported by a DCS from 2×2 interleaved MIMOcommunications services to 4×4 interleaved MIMO communications services.If the possible interleaved MIMO communications service configurationsshould be deployed in the DCS, the DCS can be reconfigured to supportthe selected interleaved MIMO communication service configurations. Inthis manner, interleaved MIMO communications services can be configuredfor a DCS using an existing infrastructure of remote units havingsubstantially non-overlapping remote coverage areas, by directing theMIMO communications streams over the configured physical layers to beprovided to the desired remote units to facilitate interleaved MIMO cellbonding of remote units.

If the infrastructure of the DCS is indicated as not being able to bechanged, the possible interleaved MIMO communications serviceconfigurations presented will involve using the existing infrastructureof remote units and their locations, but with possible differentphysical layer assignments for distribution of MIMO communicationsstreams to the remote units. If the infrastructure of the DCS isindicated as being able to be changed, the possible interleaved MIMOcommunications service configurations presented can also involvechanging (e.g., adding to) the number and/or location of remote unitsalong with possible different physical layer assignments fordistribution of MIMO communications streams to the remote units.

Before discussing examples distributing MIMO communications streams toremote units in a DCS to support configuration and/or reconfiguration ofinterleaved MIMO communications services starting at FIG. 6, anexemplary DCS is described in regards to FIGS. 3-5B.

In this regard, FIG. 3 is a schematic diagram of such an exemplary DCS300 in the form of a distributed antenna system (DAS) 302. A DAS is asystem that is configured to distribute communications signals,including wireless communications signals, from a central unit to aplurality of remote units over physical communications media, to then bedistributed from the remote units wirelessly to client devices inwireless communication range of a remote unit. The DAS 302 in thisexample is an optical fiber-based DAS that is comprised of three (3)main components. One or more interface circuits provided in the form ofradio interface circuits 304(1)-304(T) are provided in a central unit306 to receive and process (e.g., filter, amplify, route) downlinkelectrical communications signals 308D(1)-308D(S) prior to opticalconversion into downlink optical communications signals. The downlinkelectrical communications signals 308D(1)-308D(S) may be received from abase transceiver station (BTS) or baseband unit (BBU) as examples. Thedownlink electrical communications signals 308D(1)-308D(S) may be analogsignals or digital signals that can be sampled and processed as digitalinformation. The radio interface circuits 304(1)-304(T) provide bothdownlink and uplink interfaces for signal processing. The notations“1-S” and “1-T” indicate that any number of the referenced component,1-S and 1-T, respectively, may be provided.

With continuing reference to FIG. 3, the central unit 306 is configuredto accept the plurality of radio interface circuits 304(1)-304(T) asmodular components that can easily be installed and removed or replacedin a chassis. In one embodiment, the central unit 306 is configured tosupport up to twelve (12) radio interface circuits 304(1)-304(12). Eachradio interface circuit 304(1)-304(T) can be designed to support aparticular type of radio source or range of radio sources (i.e.,frequencies) to provide flexibility in configuring the central unit 306and the DAS 302 to support the desired radio sources. For example, oneradio interface circuit 304 may be configured to support the PersonalCommunication Services (PCS) radio band. Another radio interface circuit304 may be configured to support the 700 MHz radio band. In thisexample, by inclusion of these radio interface circuits 304, the centralunit 306 could be configured to support and distribute communicationssignals, including those for the communications services andcommunications bands described above as examples.

The radio interface circuits 304(1)-304(T) may be provided in thecentral unit 306 that support any frequencies desired, including but notlimited to licensed US FCC and Industry Canada frequencies (824-849 MHzon uplink and 869-894 MHz on downlink), US FCC and Industry Canadafrequencies (1850-1915 MHz on uplink and 1930-1995 MHz on downlink), USFCC and Industry Canada frequencies (1710-1755 MHz on uplink and2110-2155 MHz on downlink), US FCC frequencies (698-716 MHz and 776-787MHz on uplink and 728-746 MHz on downlink), EU R & TTE frequencies(880-915 MHz on uplink and 925-960 MHz on downlink), EU R & TTEfrequencies (1710-1785 MHz on uplink and 1805-1880 MHz on downlink), EUR & TTE frequencies (1920-1980 MHz on uplink and 2110-2170 MHz ondownlink), US FCC frequencies (806-824 MHz on uplink and 851-869 MHz ondownlink), US FCC frequencies (896-901 MHz on uplink and 929-941 MHz ondownlink), US FCC frequencies (793-805 MHz on uplink and 763-775 MHz ondownlink), and US FCC frequencies (2495-2690 MHz on uplink anddownlink).

With continuing reference to FIG. 3, the received downlink electricalcommunications signals 308D(1)-308D(S) are provided to a plurality ofoptical interfaces provided in the form of optical interface circuits310(1)-310(W) in this embodiment to convert the downlink electricalcommunications signals 308D(1)-308D(S) into downlink opticalcommunications signals 312D(1)-312D(S). The notation “1-W” indicatesthat any number of the referenced component 1-W may be provided. Theoptical interface circuits 310 may include one or more optical interfacecomponents (OICs) that contain electrical-to-optical (E-O) converters316(1)-316(W) to convert the received downlink electrical communicationssignals 308D(1)-308D(S) into the downlink optical communications signals312D(1)-312D(S). The optical interface circuits 310 support the radiobands that can be provided by the radio interface circuits 304,including the examples previously described above. The downlink opticalcommunications signals 312D(1)-312D(S) are communicated over a downlinkoptical fiber communications link 314D to a plurality of remote units318(1)-318(X) provided in the form of remote antenna units in thisexample. The notation “1-X” indicates that any number of the referencedcomponent 1-X may be provided. One or more of the downlink opticalcommunications signals 312D(1)-312D(S) can be distributed to each remoteunit 318(1)-318(X). Thus, the distribution of the downlink opticalcommunications signals 312D(1)-312D(S) from the central unit 306 to theremote units 318(1)-318(X) is in a point-to-multipoint configuration inthis example.

With continuing reference to FIG. 3, the remote units 318(1)-318(X)include optical-to-electrical (O-E) converters 320(1)-320(X) configuredto convert the one or more received downlink optical communicationssignals 312D(1)-312D(S) back into the downlink electrical communicationssignals 308D(1)-308D(S) to be wirelessly radiated through antennas322(1)-322(X) in the remote units 318(1)-318(X) to user equipment (notshown) in the reception range of the antennas 322(1)-322(X). The opticalinterface circuits 310 may also include O-E converters 324(1)-324(W) toconvert received uplink optical communications signals 312U(1)-312U(X)from the remote units 318(1)-318(X) into the uplink electricalcommunications signals 326U(1)-326U(S) as will be described in moredetail below.

With continuing reference to FIG. 3, the remote units 318(1)-318(X) arealso configured to receive uplink electrical communications signals328U(1)-328U(X) received by the respective antennas 322(1)-322(X) fromclient devices in wireless communication range of the remote units318(1)-318(X). The uplink electrical communications signals328U(1)-328U(S) may be analog signals or digital signals that can besampled and processed as digital information. The remote units318(1)-318(X) include E-O converters 329(1)-329(X) to convert thereceived uplink electrical communications signals 328U(1)-328U(X) intouplink optical communications signals 312U(1)-312U(X). The remote units318(1)-318(X) distribute the uplink optical communications signals312U(1)-312U(X) over an uplink optical fiber communication link 314U tothe optical interface circuits 310(1)-310(W) in the central unit 306.The O-E converters 324(1)-324(W) convert the received uplink opticalcommunications signals 312U(1)-312U(X) into uplink electricalcommunications signals 326U(1)-326U(X), which are processed by the radiointerface circuits 304(1)-304(T) and provided as the uplink electricalcommunications signals 330U(1)-330U(X) to a source transceiver such as abase transceiver station (BTS) or baseband unit (BBU).

Note that the downlink optical fiber communications link 314D and theuplink optical fiber communications link 314U coupled between thecentral unit 306 and the remote units 318(1)-318(X) may be a commonoptical fiber communications link, wherein for example, wave divisionmultiplexing (WDM) may be employed to carry the downlink opticalcommunications signals 312D(1)-312D(S) and the uplink opticalcommunications signals 312U(1)-312U(X) on the same optical fibercommunications link. Alternatively, the downlink optical fibercommunications link 314D and the uplink optical fiber communicationslink 314U coupled between the central unit 306 and the remote units318(1)-318(X) may be single, separate optical fiber communicationslinks, wherein for example, wave division multiplexing (WDM) may beemployed to carry the downlink optical communications signals312D(1)-312D(S) on one common downlink optical fiber and the uplinkoptical communications signals 312U(1)-312U(X) carried on a separate,only uplink optical fiber. Alternatively, the downlink optical fibercommunications link 314D and the uplink optical fiber communicationslink 314U coupled between the central unit 306 and the remote units318(1)-318(X) may be separate optical fibers dedicated to and providinga separate communications link between the central unit 306 and eachremote unit 318(1)-318(X).

The DCS 300 in FIG. 3 can be provided in an indoor environment asillustrated in FIG. 4A. FIG. 4A is a partially schematic cut-awaydiagram of a building infrastructure 332 employing the DCS 300. FIG. 4Bis a schematic diagram of the DCS 300 installed according to thebuilding infrastructure 332 in FIG. 4A.

With reference to FIG. 4A, the building infrastructure 332 in thisembodiment includes a first (ground) floor 334(1), a second floor334(2), and a Fth floor 334(F), where ‘F’ can represent any number offloors. The floors 334(1)-334(F) are serviced by the central unit 306 toprovide antenna coverage areas 336 in the building infrastructure 332.The antenna coverage area 336 is the distance in which wirelesscommunications signals can be transmitted or otherwise distributed at aminimum signal-to-noise ratio (SNR) to achieve communications with aclient device. The central unit 306 is communicatively coupled to asignal source 338, such as a BTS or BBU, to receive the downlinkelectrical communications signals 308D(1)-308D(S). The central unit 306is communicatively coupled to the remote units 318(1)-318(X) to receiveoptical uplink communications signals 312U(1)-312U(X) from the remoteunits 318(1)-318(X) as previously described in FIG. 3. The downlink anduplink optical communications signals 312D(1)-312D(S), 312U(1)-312U(X)are distributed between the central unit 306 and the remote units318(1)-318(X) over a riser cable 340 in this example. The riser cable340 may be routed through interconnect units (ICUs) 342(1)-342(F)dedicated to each floor 334(1)-334(F) for routing the downlink anduplink optical communications signals 312D(1)-312D(S), 312U(1)-312U(X)to the remote units 318(1)-318(X). The ICUs 342(1)-342(F) may alsoinclude respective power distribution circuits 344(1)-344(F) thatinclude power sources as part of a power distribution system 350,wherein the power distribution circuits 344(1)-344(F) are configured todistribute power remotely to the remote units 318(1)-318(X) to providepower for operating the power consuming components in the remote units318(1)-318(X). For example, array cables 345(1)-345(F) may be providedand coupled between the ICUs 342(1)-342(F) that contain both opticalfibers to provide the respective downlink and uplink optical fibercommunications media 314D(1)-314D(F), 314U(1)-314U(F) and powerconductors 346(1)-346(F) (e.g., electrical wire) to carry current fromthe respective power distribution circuits 344(1)-344(F) to the remoteunits 318(1)-318(X).

With reference to the DCS 300 shown in FIG. 4B, the central unit 306 mayinclude a power supply circuit 352 to provide power to the radiointerface circuits 304(1)-304(T), the optical interface circuits310(1)-310(W), and radio distribution circuits (RDCs) 354, 356. Thedownlink electrical communications signals 308D(1)-308D(S) and theuplink electrical communications signals 326U(1)-326U(S) are routed frombetween the radio interface circuits 304(1)-304(T) and the opticalinterface circuits 310(1)-310(W) through RDCs 354, 356. In oneembodiment, the RDCs 354, 356 can support sectorization in the DCS 300,meaning that only certain downlink electrical communications signals308D(1)-308D(S) are routed to certain radio interface circuits304(1)-304(T). A power supply circuit 358 may also be provided toprovide power to the optical interface circuits 310(1)-310(W). Anexternal interface 360, which may include web and network managementsystem (NMS) interfaces, may also be provided to allow configuration andcommunication to the components of the central unit 306. Amicrocontroller, microprocessor, or other control circuitry, called ahead-end controller (HEC) 362 (e.g., a controller circuit or amicroprocessor) may be included in central unit 306 to provide controloperations for the central unit 306 and the DCS 300.

The DCS 300 in FIGS. 3-4B can be configured to support MIMOcommunications services. In this regard, FIG. 5A is a schematic diagramof an exemplary the DCS 300 in FIGS. 3-4B illustrating the central unit306 and a single remote unit 318 distributing MIMO communicationsstreams to support 2×2 MIMO communications services. MIMO communicationsinvolves the use of multiple antennas at both a transmitter and receiverto improve communication performance. Remote unit 318(1) is shown inFIG. 5A and is used as an example to represent any of the remote units318(1)-318(X) in the DCS 300. FIG. 5B is a schematic diagramillustrating more detail of a downlink path and uplink path and relatedcomponents of the remote unit 318(1) in the DAS 300 illustrated in FIG.5A for supporting MIMO communications services. Common componentsillustrated for the DCS 300 in FIGS. 5A and 5B and FIGS. 3-4B are shownwith common element numbers with FIGS. 5A and 5B and thus will not bere-described.

With reference to FIG. 5A, the central unit 306 is configured to receiveelectrical downlink MIMO communications signals 308D-M from outside theDCS 300 in a signal processor 500. The central unit 306 is alsoconfigured to distribute electrical uplink MIMO communications signals308U-M, received from a wireless client device 502, to other systems.The signal processor 500 may be configured to provide the electricaldownlink MIMO communications signals 308D-M to a mixer 504, which may bean IQ signal mixer in this example. The mixer 504 is configured toconvert the electrical downlink MIMO communications signals 308D-M to IQsignals in one example. The mixer 504 is driven by a frequency signal506 that is provided by a local oscillator 508. Frequency conversion isoptional. In this embodiment, it is desired to up-convert the frequencyof the electrical downlink MIMO communications signals 308D-M to ahigher frequency to provide electrical downlink MIMO communicationssignals 312D-M(E) to provide for a greater bandwidth capability beforedistributing the electrical downlink MIMO communications signals312D-M(E) to the remote unit 318(1). For example, the up-conversioncarrier frequency may be provided as an extremely high frequency (e.g.,approximately 30 GHz to 300 GHz).

With continuing reference to FIG. 5A, because the communication mediumbetween the central unit 306 and the remote unit 318(1) is the opticalfiber communications medium 314D, 314U in this example, the electricaldownlink MIMO communications signals 312D-M(E) are converted to opticalsignals by an electro-optical converter 510. The electro-opticalconverter 510 includes components to receive a light wave 512 from alight source 514, such as a laser. The light wave 512 is modulated bythe frequency oscillations in the electrical downlink MIMOcommunications signals 312D-M(E) to provide optical downlink MIMOcommunications signals 312D-M(O) over the downlink optical fiber 314D tothe remote unit 318(1). The electro-optical converter 510 may beprovided so that the electrical downlink MIMO communications signals312D-M(E) are provided as radio-over-fiber (RoF) communications signals.

With continuing reference to FIG. 5A, the optical downlink MIMOcommunications signals 312D-M(O) are received by an opticalbi-directional amplifier 516, which is then provided to a MIMO splittercircuit 518 in the remote unit 318(1). The MIMO splitter 518 is providedso that the optical downlink MIMO communications signals 312D-M(O) canbe split among two separate downlink communication paths 520(1), 520(2)to be radiated over two separate MIMO antennas 322(1)(1), 322(1)(2)provided in two separate MIMO transmitters 522(1), 522(2) configured inMIMO configuration. The MIMO antennas 322(1)(1), 322(1)(2) areconfigured to be bonded, meaning that both MIMO antennas 322(1)(1),322(1)(2) are co-located within the same remote unit 318(1) to eachprovide substantially overlapping MIMO coverage areas designed tosupport MIMO communications with a particular wireless client device 502in communications range of their MIMO coverage areas. The MIMO splittercircuit 518 in the remote unit 318(1) is an optical splitter since thereceived optical downlink MIMO communications signals 312D-M(O) areoptical signals. In each downlink communication path 520(1), 520(2),downlink optical-to-electrical converters 524D(1), 524D(2) are providedto convert the optical downlink MIMO communications signals312D-M(O)(1), 312D-M(O)(2) to electrical downlink MIMO communicationssignals 308D-M(1), 308D-M(2). The uplink path of the communicationspaths 520(1), 520(2) in the remote unit 318(1) is illustrated in FIG.5B. As illustrated in FIG. 5B, uplink electrical-to-optical converters524U(1), 524U(2) are also provided in the remote unit 318(1) to convertelectrical uplink MIMO communications signals 308U-M(1), 308U-M(2)received from the wireless client device 502 to optical uplink MIMOcommunications signals 312U-M(O)(1), 312U-M(O)(2) to be communicatedover the uplink optical fiber 314U(1), 314U(2) to the central unit 306.

With reference back to FIG. 5A, the wireless client device 502 includestwo MIMO receivers 528(1), 528(2) that include MIMO receiver antennas530(1), 530(2) also configured in MIMO configuration. The MIMO receiverantennas 530(1), 530(2) are configured to receive the electricaldownlink MIMO communications signals 308D-M(1), 308D-M(2) wirelesslyfrom the remote unit 318(1). Mixers 532(1), 532(2) are provided andcoupled to the MIMO receiver antennas 530(1), 530(2), respectively, inthe wireless client device 502 to provide frequency conversion of theelectrical downlink MIMO communications signals 308D-M(1), 308D-M(2). Alocal oscillator 534 is provided that is configured to provideoscillation signals 536(1), 536(2) to the mixers 532(1), 532(2),respectively, for frequency conversion. In this embodiment, theelectrical downlink MIMO communications signals 308D-M(1), 308D-M(2) aredown converted back to their native frequency as received by the centralunit 306. The down converted electrical downlink MIMO communicationssignals 308D-M(1), 308D-M(2) are then provided to a signal analyzer 538in the wireless client device 502 for any processing desired.

Even with the potential doubling of bandwidth in the DCS 300 in FIGS. 5Aand 5B by being configured to support MIMO communications services, thewireless client device 502 must still be within range of two antennas322(1), 322(2) of a remote unit 318 (e.g., antennas 322(1)(1), 322(1)(2)of remote unit 318(1)) to properly operate in MIMO configuration withincreased bandwidth. Otherwise, the full benefits of increased bandwidthof MIMO technology provided in the DCS 300 may not be realized. Ensuringuniform MIMO coverage in coverage areas of the DCS 300 may beparticularly important for newer cellular standards, such as Long TermEvolution (LTE), where increased bandwidth requirements are expected byusers of client devices 502 in all coverage areas. Thus, it is desiredto provide uniform coverage areas in a DCS, such as DCS 300,particularly in the edges of MIMO coverage cells. However, as discussedabove, providing traditional MIMO remote unit bonding between co-locatedremote units 318 in the DCS 300 in FIGS. 5A and 5B may still providenon-uniform MIMO coverage areas unless a high density of remote units318 are provided, thereby increasing cost and complexity.

In this regard, FIG. 6 is a schematic diagram of exemplary adjacentremote units 318(1), 318(2) in the DCS 300 in FIGS. 5A and 5B, havingexemplary substantially non-overlapping remote coverage areas 600(1),600(2) and located a defined distance D₁ from each other to be capableof being interleaved MIMO cell bonded together to support interleavedMIMO communications services. For example, if a wireless client device502 receives a downlink communications signal from a remote unit 318(1),318(2) greater than 12 dB for example, the wireless client device 502may engage in SISO communications with a remote unit 318(1), 318(2).However, if a wireless client device 502 receives a downlinkcommunications signal from a remote unit 318(1), 318(2) less than 12 dBfor example, the wireless client device 502 may engage in interleavedMIMO communications with the remote units 318(1), 318(2), which may beachievable at distance D₁ such that the remote coverage areas 600(1),600(2) are substantially non-overlapping. Note that FIG. 6 illustratestwo remote units 318(1), 318(2), but the interleaved MIMO cell bondedremote units could be any of the remote units 318(1)-318(X) in the DCS300.

In this example, the interleaved MIMO communication services are 2×2MIMO communications services. Interleaved MIMO communications servicesin this example involves configuring the adjacent remote units 318(1),318(2) separated by the prescribed distance D₁ in the DCS 300 to haverespective, adjacent, substantially non-overlapping remote coverageareas 600(1), 600(2) to each receive a MIMO communications stream602(1), 602(2). The MIMO communications streams 602(1), 602(2) are MIMOcommunications signals that are directed to the same wireless clientdevice 502 to provide MIMO communications services. In this regard, theMIMO communications signals distributed by the central unit 306 to therespective remote units 318(1), 318(2) include downlink optical MIMOcommunications signals 312D-M(1), 312D-M(2) as also previouslyillustrated in FIG. 5A. The remote units 318(1), 318(2) are configuredto distribute the downlink optical MIMO communications signals312D-M(1), 312D-M(2) as downlink electrical MIMO communications signals308D-M(1), 308D-M(2) in the respective remote coverage areas 600(1),600(2) to a wireless client device 502. The MIMO communications signalscan also include uplink electrical MIMO communications signals308U-M(1), 308U-M(2) received by the remote units 318(1), 318(2) from awireless client device 502 to be distributed by the respective remoteunits 318(1), 318(2) as uplink electrical MIMO communications signals308U-M(1), 308U-M(2) to the central unit 306. The remote unit 318(1)supports communicating the MIMO communications stream 602(1) in itsremote coverage area 600(1), and the remote unit 318(2) supportscommunicating the MIMO communications streams 602(2) in its respectiveremote coverage area 600(2). If a wireless client device 502 is outsideof the remote coverage area 600(1), 600(2) of one remote unit 318(1),318(2), but not the other, the wireless client device 502 can stillcommunicate with the in-range remote unit 318(1), 318(2) for SISOcommunications services.

FIG. 7 is a schematic diagram of the adjacent remote units 318(1)-318(4)in the DCS 300 in FIG. 6 to further describe interleaved MIMO cellbonding that occurs between the remote units 318(1)-318(4) based on thedistances D₂ and D₃ between the remote units 318(1)-318(4). Remote units318(1), 318(3) are co-located with each other at distance D₂ such thattheir respective remote coverage areas 600(1), 600(3) are substantiallyoverlapping. Remote units 318(2), 318(4) are shown co-located with eachother by distance D₂ (e.g., within 2 meters), which is also close enoughto each other such that their respective remote coverage areas 600(2),600(4) are substantially overlapping to provide 100% MIMO coverage inthis example. For example, area 604(1) is underneath remote unit 318(3),which is in both remote coverage areas 600(1), 600(3). Area 604(2) isbetween the remote units 318(1), 318(3), which is also in both remotecoverage areas 600(1), 600(3). As an example, distance D₂ of six (6)meters or less may provide for the remote units 318(1), 318(3) toprovide 100% MIMO coverage for client devices within their remotecoverage areas 600(1), 600(3) and provide for the remote units 318(2),318(4) to provide 100% MIMO coverage for client devices within theirremote coverage areas 600(2), 600(4).

Alternatively, as another example, remote units 318(1), 318(2) can belocated a distance D₃ (e.g., >6 meters apart) still close enough to eachother such that their respective remote coverage areas 600(2), 600(4)are not substantially overlapping to still provide MIMO coverage even ifless than 100% MIMO coverage. For example, assume that only remote units318(1) and 318(2) were illustrated in FIG. 7 and located a distance D₃apart from each other (e.g., >=12 meters (m)), greater than distance D₂such that their respective remote coverage areas 600(1), 600(2) areoverlapping, but not substantially overlapping. At this distance D₃,remote units 318(1), 318(2) can still achieve interleaved MIMO cellbonding, but at a reduced MIMO coverage. For example, at distance D₃ ofapproximately six (6) m to twenty-two (22) m, the remote units 318(1),318(2) with their remote coverage areas 600(1), 600(2) may still provide65% to 95% MIMO coverage through interleaved MIMO cell bonding eventhough their respective remote coverage areas 600(1), 600(2) aresubstantially non-overlapping. This reduced MIMO coverage may be anacceptable tradeoff to provide MIMO coverage in a DCS, such as DCS 300,with fewer remote units 318 deployed to save cost and/or complexity.

FIG. 8 is a graph 800 that illustrates an exemplary percentage of theremote coverage area 600 for MIMO communications services as a functionof distance D_(X) between the remote units 318(1)-318(X). Line 802 showsthe percentage of remote coverage area 600 supporting MIMOcommunications services for a traditional MIMO communications service,such as between remote units 318(1), 318(3) and between remote units318(2), 318(4) in FIG. 7. For example, according to line 802 in FIG. 8,approximately 80% of the remote coverage areas 600(1), 600(3) supporttraditional MIMO communications services when the remote units 318(1),318(3) are located from each other at distance D₂ within approximatelysix (6) meters.

With reference back to FIG. 7, it has been discovered that when remoteunits 318(1), 318(X), such as the remote units 318(1), 318(2) are notco-located and located further away at prescribed distance D₃ such thattheir respective remote coverage areas 600(1), 600(2) are substantiallynon-overlapping, interleaved MIMO communications services can still beachieved. Interleaved MIMO cell bonding occurs between the remote units318(1), 318(2) by their remote coverage areas 600(1), 600(2)overlapping, but not substantially overlapping in this example. Forexample, area 604(3) is an area wherein the remote coverage areas600(1), 600(2) overlap at the cell edge of the remote coverage areas600(1), 600(2) of the remote units 318(1), 318(2). This is shown byexample in the graph 800 in FIG. 8, where line 804 shows the percentageof remote coverage area 600 for MIMO communications services for aninterleaved MIMO communications service, such as between remote units318(1), 318(2) in FIG. 7. For example, according to line 804 in FIG. 8,approximately 65% of the remote coverage areas 600(1), 600(2) supportMIMO communications services when the remote units 318(1), 318(2) arelocated from each other at distance D₃ within approximately eight (18)meters. SISO communications services are still supported by the remoteunits 318(1), 318(2) even for the 35% of the remote coverage areas600(1), 600(2) that do not support MIMO communications services. Thesize of the remote coverage areas 600(1), 600(2) supporting interleavedMIMO communications services formed by the interleaved MIMO cell bondingbetween the remote units 318(1), 318(2) is a function of the distanceD_(X) between the remote units 318(1), 318(2), because this distanceaffects the signal quality level required by a wireless client device toreceive the MIMO communications streams 600(1), 600(2). If a wirelessclient device does not have an acceptable and/or higher communicationssignal quality with the antenna of a single remote unit 318(1), 318(2),the wireless client device will engage in SISO communications with theremote unit 318(1), 318(2). However, if a wireless client device doesnot have acceptable and/or higher communications signal quality with asingle remote unit 318(1), 318(2), the wireless client device willengage in interleaved MIMO communications through the interleaved MIMOcell bonded remote units 318(1), 318(2).

Thus, interleaved MIMO cell bonding between the remote units 318(1),318(2) allows MIMO communications services to still be supported in theDCS 300 without having to necessarily co-locate the remote units 318(1),318(2), or provide multiple radios in each remote unit 318(1), 318(2) toachieve sufficient MIMO communication services, thus reducing cost andcomplexity. Thus, MIMO communications services can be provided in theDCS 300 with less remote units 318(1)-318(X). This also allows anexisting infrastructure of installed remote units 318(1)-318(X)configured to support SISO communications, to support interleaved MIMOcommunication services, based on a trade-off of the number of remoteunits 318(1)-318(X) and distance D_(X) therebetween versus percentage oftheir remote coverage areas 600 that support MIMO communicationsservices. More sparse and lower cost remote unit deployments can stillprovide substantially uniform high-capacity MIMO communicationscoverage.

An existing infrastructure of installed remote units in a DCS configuredto support SISO communications, such as the remote units 318(1)-318(X)in the DCS 300 in FIGS. 5A and 5B, can be configured or re-configured tosupport interleaved MIMO communication services taking the example ofFIG. 6 if the DCS 300 can be configured or re-configured to route MIMOcommunications streams 602(1), 602(2). In this regard, FIG. 9A is aschematic diagram 900(1) illustrating a configuration of the remoteunits 318(1)-318(X) that can be provided in DCS 300 in FIG. 5A tosupport SISO communications streams to designated remote units318(1)-318(X) in the DCS 300. Each circle ‘A’ represents a single remoteunit 318 and its remote coverage area 600 receiving MIMO communicationsstream A. However, as shown in the schematic diagram 900(2) in FIG. 9B,the same number of remote units 318(1)-318(X) and their respectivelocations are provided, but the remote units 318(1)-318(X) areconfigured to support 2×2 interleaved MIMO communications services. TheMIMO communications streams ‘A’ and ‘B’ are routed to the remote units318(1)-318(X) interleaved to provide a 2×2 interleaved MIMO cell bondingconfiguration to support 2×2 interleaved MIMO communications services.Thus, by simply re-routing the MIMO communications streams ‘A’ and ‘B’to the existing remote units 318(1)-318(X) in FIG. 9A, the remote units318(1)-318(X) can be configured to migrate from only supporting SISOcommunications services to 2×2 interleaved MIMO communications services.

Even further, FIG. 9C is a schematic diagram 900(3) illustrating anexemplary 4×4 interleaved MIMO cell bonding configuration that can beconfigured and/or re-configured in the DCS 300 in FIG. 5A based onconfiguring and/or re-configuring the distribution of MIMOcommunications streams 602 to designated remote units 318(1)-318(X) inthe DCS 300. Again, the same number of remote units 318(1)-318(X) andtheir respective locations are provided, but the remote units318(1)-318(X) are configured to support 4×4 interleaved MIMOcommunications services. The MIMO communications streams ‘A’, ‘B’, ‘C’,and ‘D’ are routed to the remote units 318(1)-318(X) interleaved toprovide a 4×4 interleaved MIMO cell bonding configuration to support 4×4interleaved MIMO communications services. Thus, by simply re-routing theMIMO communications streams MIMO communications streams ‘A’, ‘B’, ‘C’,and ‘D’ to the existing remote units 318(1)-318(X) in FIG. 9A or 9B, theremote units 318(1)-318(X) can be configured to migrate from onlysupporting SISO communications services, or 2×2 interleaved MIMOcommunications services, to 4×4 interleaved MIMO communicationsservices.

To configure or re-configure the DCS 300 to support the desiredcommunications services, whether it be SISO communications services orinterleaved MIMO communication services, the DCS 300 provides differentphysical layers that are maintained from the central unit 306 to theremote units 318(1)-318(X). In this manner, the central unit 306 can beconfigured or reconfigured to distribute communications signals, to thedesired physical layers in the DCS 300 to in turn distribute thecommunications signals to the desired remote units 318(1)-318(X) toprovide the desired communications services. In this manner, as anexample, interleaved MIMO communications services can be configured forthe DCS 300 using an existing infrastructure of remote units318(1)-318(X) having substantially non-overlapping remote coverage areas600(1)-600(X), by directing the MIMO communications streams over theconfigured physical layers to be provided to the desired remote units318(1)-318(X) to facilitate interleaved MIMO cell bonding of adjacentremote units 318(1)-318(X). For example, substantially non-overlappingcoverage areas may mean that the coverage areas do not overlap by morethan 70%, 60%, 50%, or less than 50% as examples.

In this regard, FIG. 10A is a schematic diagram illustrating the DCS 300in FIGS. 5A and 5B configured to support distribution of SISOcommunications streams to remote units 318(1)-318(X), 318(8) (where‘X’=8 in this example) to support SISO communication services. Theremote units 318(1)-318(8) are installed in the DCS 300 according to thedesired locations and desired separation distances (e.g., between 12-15meters) to provide the desired remote coverage areas. The central unit306 is configured to receive downlink SISO communications signals308D-S(A)-308D-S(C) from a signal source, such as a base transceiverstation (BTS) or baseband unit (BBU) as examples, where each downlinkSISO communications signals 308D-S(A)-308D-S(C) represents a particularcommunications band ‘A’, ‘B’, ‘C’ for a particular communicationsservice. As previously discussed in regard to FIG. 3, the central unit306 includes the radio interface circuits 304(1)-304(T) that areconfigured receive and process the received downlink SISO communicationssignals 308D-S(A)-308D-S(C). As also discussed in regard to FIG. 3, inthis example, the central unit 306 also includes the optical interfacecircuits 310(1)-310(W) to convert the received downlink SISOcommunications signals 308D-S(A)-308D-S(C) into optical downlink SISOcommunications signals 308D-S(A)-308D-S(C). A routing circuit 1000 isalso provided, which may also be in the central unit 306, to route thedownlink SISO communications signals 308D-S(A)-308D-S(C) to the desiredremote units 318(1)-318(8), 318(X) (where ‘X’=8 in this example)according to a routing configuration 1004 for the DCS 300. In thisregard, the DCS 300 includes physical layers 1002(1)-1002(8) dedicatedto each of the remote units 318(1)-318(8). Each physical layer1002(1)-1002(8) is dedicated to one remote unit 318(1)-318(8) andmaintained from the central unit 306 to the remote units 318(1)-318(8)in a one-to-one connectivity in this example. In this example, thephysical layers 1002(1)-1002(8) are the dedicated communications linksin the form of optical fiber communications links 314(1)-314(8). Thephysical layers 1002(1)-1002(8) can be downlink physical layers onlydedicated to carrying downlink communications signals to the remoteunits 318(1)-318(8) or also configured to carry uplink communicationssignals from the remote units 318(1)-318(8) to the central unit 306.Each optical fiber communications link 314(1)-314(8) can separateoptical fiber communications links for carrying downlink and uplinkcommunications signals separately as shown in FIG. 3, or a singleoptical fiber communications link for carrying uplink and downlinkcommunications signals. For example, FIG. 10B is a schematic diagramillustrating a communications services layout 1006 of remote units318(1)-318(8) in the DCS 300 in FIG. 10A installed in a building 1008.The remote units 318(1)-318(8) are located in building 1008 according tothe desired locations to provide the desired remote coverage areas.

With reference back to FIG. 10A, the routing circuit 1000 is configuredto control the routing of the optical interface circuits 310(1)-310(W)to the physical layers 1002(1)-1002(8) according to the routingconfiguration 1004 to control which downlink SISO communications signals308D-S(A)-308D-S(C) are routed to the remote units 318(1)-318(8). Therouting circuit 1000 controls the spatial deployment of communicationssignals to the remote units 318(1)-318(8). In this example, the HEC 362as shown in FIG. 4B may be configured to program the routingconfiguration 1004 of the routing circuit 1000. The routingconfiguration 1004 may be stored in a memory or other circuit settings.In this example, the routing configuration 1004 is configured to causethe routing circuit 1000 to route the downlink SISO communicationssignals 308D-S(A) to remote units 318(1)-318(3), the downlink SISOcommunications signals 308D-S(B) to remote units 318(4)-318(6), and thedownlink SISO communications signals 308D-S(C) to remote units318(7)-318(8). The remote units 318(1)-318(8) are also configured toreceive and distribute received respective uplink SISO communicationssignals 308U-S(A)(1)-308U-S(A)(3), 308U-S(B)(1)-308U-S(B)(3),308U-S(C)(1)-308U-S(C)(2) over the respective dedicated physical layers1002(1)-1002(8) to the central unit 306 to be distributed back to anetwork, such as BTS or BBU. The routing circuit 1000 routes thereceived uplink SISO communications signals 308U-S(A)(1)-308U-S(A)(3),308U-S(B)(1)-308U-S(B)(3), 308U-S(C)(1)-308U-S(C)(2) from the dedicatedphysical layers 1002(1)-1002(8) to particular radio interface circuits304(1)-304(T) according to the routing configuration 1004.

It may be desired for DCS 300 in FIG. 10A to support MIMO communicationsservices, such as 2×2 MIMO communications services. It may be desired toconfigure the DCS 300 in FIG. 10A to support MIMO communications withouthaving to change the location of the remote units 318(1)-318(X). In thisregard, by changing the routing configuration 1004 to provide forinterleaved MIMO cell bonding between adjacent remote units318(1)-318(8) as previously discussed, it may be possible tore-configure the DCS 300 to support MIMO communications without havingto change the location of the remote units 318(1)-318(8) or with minimalrelocating or providing of additional remote units 318(1)-318(8). Thisprovides an upgrade path for customers of the DCS 300 in FIG. 10Ashould, for example, only SISO communications services be initiallydesired to be supported, but then MIMO communications services may bedesired to be supported in the future.

In this regard, FIG. 11A is a schematic diagram illustrating the DCS 300in FIGS. 5A and 5B configured to support distribution of SISOcommunications streams to remote units 318(1)-318(X), 318(8) (where‘X’=8 in this example) to support MIMO communications services. Theremote units 318(1)-318(8) are installed in the DCS 300 according to thedesired locations and desired separation distances (e.g., between 12-15meters) to provide the desired remote coverage areas. The central unit306 is configured to receive downlink MIMO communications signals308D-M(A), 308D-M(B) for MIMO communications streams ‘A’ and ‘B’, suchas from a BTS or BBU as examples. Each downlink MIMO communicationssignals 308D-M(A), 308D-M(B) represents a particular MIMO communicationsstream ‘A’, ‘B’ for a communications service. As previously discussed inregard to FIG. 3, the central unit 306 includes the radio interfacecircuits 304 that are configured to receive and process the receiveddownlink MIMO communications signals 308D-M(A), 308D-M(B). Thisprocessing may include splitting the downlink MIMO communicationssignals 308D-M(A), 308D-M(B) so that each can be deployed to multipleremote units 318(1)-318(8) according to the routing configuration 1004.As also discussed in regard to FIG. 3, in this example, the central unit306 also includes the optical interface circuits 310 to convert thereceived downlink MIMO communications signals 308D-M(A), 308D-M(B) intooptical downlink MIMO communications signals 308D-M(A), 308D-M(B). Therouting circuit 1000 is configured to route the downlink MIMOcommunications signals 308D-M(A), 308D-M(B) to the desired remote units318(1)-318(8), 318(X) (where ‘X’=8 in this example) according to therouting configuration 1004 for the DCS 300. In this regard, the DCS 300includes the physical layers 1002(1)-1002(8) dedicated to each of theremote units 318(1)-318(8). The physical layers 1002(1)-1002(8)dedicated to each of the remote units 318(1)-318(8) are maintained fromthe central unit 306 to the remote units 318(1)-318(8). In this example,the physical layers 1002(1)-1002(8) are the dedicated communicationslinks in the form of optical fiber communications links 314(1)-314(8).Each optical fiber communications link 314(1)-314(8) can separateoptical fiber communications links for carrying downlink and uplinkcommunications signals separately as shown in FIG. 3, or a singleoptical fiber communications link for carrying uplink and downlinkcommunications signals.

For example, FIG. 11B is a schematic diagram illustrating acommunications services layout 1100 of sixteen (16) remote units318(1)-318(16) in the DCS 300 in FIG. 11A installed in the building1008. The remote units 318(1)-318(16) may be located in building 1008 inthe same configuration as in the communications services layout 1006 inFIG. 10B. In the communications services layout 1100, the remote units318(1)-318(16) are located approximately 6 meters from each other. Areas1102 in the building 1008 illustrated in FIG. 11B are areas where awireless client device can receive a downlink communications signal froma remote unit 318(1)-318(16) above a threshold signal strength (e.g.,reference signal receive power (RSRP)) sufficient to engage in SISOcommunications (e.g., >12 dB). Areas 1104 in the building 1008illustrated in FIG. 11B are areas where a wireless client device cannotreceive a downlink communications signal from a remote unit318(1)-318(16) above a threshold signal strength sufficient to engage inSISO communications (e.g., <12 dB), and thus 2×2 interleaved MIMOcommunications are supported according to the interleaved MIMOcommunications configuration for the DCS 300 illustrated in FIG. 11A.

FIG. 11C is a schematic diagram illustrating another communicationsservices layout 1110 of remote units 318(1)-318(8) in the DCS 300 inFIG. 11A installed in the building 1008. In the communications serviceslayout 1110, the remote units 318(1)-318(8) are located approximately 12meters from each other. Areas 1112 in the building 1008 illustrated inFIG. 11C are areas where a wireless client device can receive a downlinkcommunications signal from a remote unit 318(1)-318(8) above a thresholdsignal strength (e.g., reference signal receive power (RSRP)) sufficientto engage in SISO communications (e.g., >12 dB). Areas 1114 in thebuilding 1008 illustrated in FIG. 11C are areas where a wireless clientdevice cannot receive a downlink communications signal from a remoteunit 318(1)-318(8) above a threshold signal strength sufficient toengage in SISO communications (e.g., <12 dB), and thus 2×2 interleavedMIMO communications are supported according to the interleaved MIMOcommunications configuration for the DCS 300 illustrated in FIG. 11A.Note that the area 1114 in the building 1008 in FIG. 11C where 2×2interleaved MIMO communications services are supported is smaller thanthe area 1104 in building 1008 in FIG. 11B, because the remote units318(1)-318(8) are spaced farther apart in the building 1008 in FIG. 11C.For example, area 1104 in FIG. 11B wherein the 2×2 interleaved MIMOcommunications services is supported may be approximately 97% of thetotal areas 1102, 1104 where communication services are supported by theDCS 300, whereas area 1114 in FIG. 11C may be approximately 76% of thetotal areas 1112, 1114 where communication services are supported.Nevertheless, a 76% area supporting interleaved MIMO communicationsservices is provided with approximately half of the number of remoteunits 318(1)-318(8), which may be an acceptable trade-off.

With reference back to FIG. 11A, the routing circuit 1000 is configuredto control the routing of the optical interface circuits 310(1)-310(W)to the physical layers 1002(1)-1002(8) according to the routingconfiguration 1004 to control which downlink SISO communications signals308D-S(A)-308D-S(C) are routed to the remote units 318(1)-318(8). Inthis example, the HEC 362 as shown in FIG. 4B may be configured toprogram the routing configuration 1004 of the routing circuit 1000. Therouting configuration 1004 may be stored in a memory or other circuitsettings. In this example, the routing configuration 1004 is configuredto cause the routing circuit 1000 to route the downlink MIMOcommunications signals 308D-M(A) to remote units 318(1), 318(3), 318(5),318(7), and the downlink MIMO communications signals 308D-M(B) to remoteunits 318(2), 318(4), 318(6), 318(8). In this regard, remote unit 318(1)is interleaved MIMO cell bonded to adjacent remote units 318(2), 318(3),remote unit 318(2) is interleaved MIMO cell bonded to adjacent remoteunits 318(1), 318(4), remote unit 318(3) is interleaved MIMO cell bondedto adjacent remote units 318(1), 318(4), as so on, as shown in FIG. 11A.The remote units 318(1)-318(8) are also configured to receive anddistribute received respective uplink MIMO communications signals308U-M(A)(1)-308U-M(A)(4), 308U-M(B)(1)-308U-M(B)(4) from the respectiveremote units 318(1), 318(3), 318(5), 318(7), 318(2), 318(4), 318(6),318(8) over dedicated physical layers 1002(1)-1002(8) to the centralunit 306 to be distributed back to a network, such as BTS or BBU. Therouting circuit 1000 routes the received uplink MIMO communicationssignals 308U-M(A)(1)-308U-M(A)(4), 308U-M(B)(1)-308U-M(B)(4) from thededicated physical layers 1002(1)-1002(8) to particular radio interfacecircuits 304(1)-304(T) according to the routing configuration 1004.

Note that while FIG. 11A shows downlink MIMO communications signals308D-M(A) are routed to physical layers 1002(1), 1002(3), 1002(5), and1002(7) distributed to remote units 318(1), 318(3), 318(5), and 318(7),and downlink MIMO communications signals 308D-M(B) are routed tophysical layers 1002(2), 1002(4), 1002(6), and 1002(8) to be distributedto remote units 318(2), 318(4), 318(6), and 318(8), it is also possibleto route the same downlink MIMO communications signal (e.g., downlinkMIMO communications signal 308D-M(A) and/or downlink MIMO communicationssignal 308D-M(B)) to the same physical layer 1002(1)-1002(8) to berouted to the same remote unit 318(1)-318(8). for example downlink MIMOcommunications signal 308D-M(A) and downlink MIMO communications signal308D-M(B) could be routed to the same remote unit 318(1)-318(8) isconfigured to provide co-located MIMO communications services. Differentgroupings of downlink MIMO communications signal (e.g., downlink MIMOcommunications signal 308D-M(A) and/or downlink MIMO communicationssignal 308D-M(B)) can be routed to groupings of the remote units318(1)-318(8).

It may also be desired for DCS 300 in FIG. 11A to support enhanced MIMOcommunications services, such as 4×4 MIMO communications services. Itmay be desired to configure the DCS 300 in FIG. 11A to support MIMOcommunications without having to change the location of the remote units318(1)-318(X). In this regard, by changing the routing configuration1004 to provide for interleaved MIMO cell bonding between adjacentremote units 318(1)-318(8) as previously discussed, it may be possibleto re-configure the DCS 300 to support 4×4 MIMO communications withouthaving to change the location of the remote units 318(1)-318(8) or withminimal relocating or providing of additional remote units318(1)-318(8). This provides an upgrade path for customers of the DCS300 in FIG. 11A should, for example, only 2×2 MIMO communicationsservices be initially desired to be supported, but then 4×4 MIMOcommunications services may be desired to be supported in the future.

In this regard, FIG. 12 is a schematic diagram illustrating the DCS 300in FIGS. 5A and 5B configured to support distribution of 4×4 interleavedMIMO communications streams to remote units 318(1)-318(X), 318(8) (where‘X’=8 in this example) to support MIMO communications services. Theremote units 318(1)-318(8) are installed in the DCS 300 according to thedesired locations and desired separation distances (e.g., between 12-15meters) to provide the desired remote coverage areas. The central unit306 is configured to receive downlink MIMO communications signals308D-M(A)-308D-M(D) for MIMO communications streams ‘A’, ‘B’, ‘C’, and‘D’ such as from a BTS or BBU as examples. Each downlink MIMOcommunications signal 308D-M(A)-308D-M(D) represents a particular MIMOcommunications stream ‘A’, ‘B’, ‘C’, and ‘D’ for a communicationsservice. As shown in FIG. 12, the central unit 306 includes radiointerface circuits 304A, 304B that are configured to receive and processthe respective received downlink MIMO communications signals 308D-M(A),308D-M(B) and 308D-M(C), 308D-M(D). As also illustrated in this examplein FIG. 12, the central unit 306 includes the optical interface circuits310A, 310B to convert the respective received downlink MIMOcommunications signals 308D-M(A), 308D-M(B), and 308D-M(C), 308D-M(D)into optical downlink MIMO communications signals 308D-M(A), 308D-M(B)and 308D-M(C), 308D-M(D). The routing circuit 1000 is configured toroute the downlink MIMO communications signals 308D-M(A), 308D-M(B) and308D-M(C), 308D-M(D) to the desired remote units 318(1)-318(8), 318(X)(where ‘X’=8 in this example) according to the routing configuration1004 for the DCS 300. In this regard, the DCS 300 includes the physicallayers 1002(1)-1002(8) dedicated to each of the remote units318(1)-318(8). The physical layers 1002(1)-1002(8) dedicated to each ofthe remote units 318(1)-318(8) are maintained from the central unit 306to the remote units 318(1)-318(8). In this example, the physical layers1002(1)-1002(8) are the dedicated communications links in the form ofoptical fiber communications links 314(1)-314(8). Each optical fibercommunications link 314(1)-314(8) can separate optical fibercommunications links for carrying downlink and uplink communicationssignals separately as shown in FIG. 3, or a single optical fibercommunications link for carrying uplink and downlink communicationssignals.

With continuing reference to FIG. 12, the routing circuit 1000 isconfigured to control the routing of the optical interface circuits310A, 310B to the physical layers 1002(1)-1002(8) according to therouting configuration 1004 to control which downlink MIMO communicationssignals 308D-M(A)-308D-M(D) routed to the remote units 318(1)-318(8). Inthis example, the HEC 362 as shown in FIG. 4B may be configured toprogram the routing configuration 1004 of the routing circuit 1000. Therouting configuration 1004 may be stored in a memory or other circuitsettings. In this example, the routing configuration 1004 is configuredto cause the routing circuit 1000 to route the downlink MIMOcommunications signals 308D-M(A) to remote units 318(1) and 318(5),downlink MIMO communications signals 308D-M(B) to remote units 318(2)and 318(6), downlink MIMO communications signals 308D-M(C) to remoteunits 318(3) and 318(7), and downlink MIMO communications signals308D-M(D) to remote units 318(4) and 318(8). In this regard, remote unit318(1) is interleaved MIMO cell bonded to adjacent remote units318(2)-318(4), remote unit 318(2) is interleaved MIMO cell bonded toadjacent remote units 318(1), 318(3), 318(4), remote unit 318(3) isinterleaved MIMO cell bonded to adjacent remote units 318(1), 318(4),318(5), and so on, as shown in FIG. 12. The remote units 318(1)-318(8)are also configured to receive and distributed received respectiveuplink MIMO communications signals 308U-M(A)(1)-308U-M(A)(2),308U-M(B)(1)-308U-M(B)(2), 308U-M(C)(1)-308U-M(C)(2), and308U-M(D)(1)-308U-M(D)(2) from the respective remote units 318(1),318(5), 318(2), 318(6), 318(3), 318(7), 318(4), 318(8) over dedicatedphysical layers 1002(1)-1002(8) to the central unit 306 to bedistributed back to a network, such as BTS or BBU. The routing circuit1000 routes the received uplink MIMO communications signals308U-M(A)(1)-308U-M(A)(2), 308U-M(B)(1)-308U-M(B)(2),308U-M(C)(1)-308U-M(C)(2), and 308U-M(D)(1)-308U-M(D)(2) from thededicated physical layers 1002(1)-1002(8) to particular radio interfacecircuits 304A, 304B according to the routing configuration 1004.

To support configuration or reconfiguration of interleaved MIMOcommunications services in the DCS 300, the DCS 300 can also supportsimulating the interleaved MIMO performance of the DCS 300 to determinepossible interleaved MIMO communication service configurations to bepresented to a technician or customer. In this regard, the interleavedMIMO performance of an existing DCS 300 infrastructure is simulated.This simulation can involve the use of simulation software that may beresident in the DCS 300 or located outside the DCS 300, such as in thecloud accessible to the DCS 300 to be executed by a processor circuit,such as the HEC 362. Alternatively, the simulation software may beresident and executed in a standalone computer system outside of the DCS300. The simulated interleaved MIMO performance of an existing DCS 300can be used to determine possible interleaved MIMO configurations in theDCS 300 along with the associated configurations and changes needed torealize such possible interleaved MIMO configurations. For example, thesimulation may involve creating a “heat” map of both SISO andinterleaved MIMO remote coverage areas of the remote units 318(1)-318(X)in the DCS 300 based on existing configurations for and locations of theremote units 318(1)-318(X) and the assigned routing of MIMOcommunications streams over the physical layers 1002(1)-1002(X) to theremote units 318(1)-318(X). These possible interleaved MIMOcommunications service configurations can then be presented to atechnician or customer to determine if any of the possible interleavedMIMO communications service configurations should be deployed in the DCS300. For example, one possible interleaved MIMO communication serviceconfiguration may be to change the supported MIMO communicationsservices from 2×2 interleaved MIMO communications services to 4×4interleaved MIMO communications services. If the possible interleavedMIMO communications service configurations should be deployed in the DCS300, the DCS 300 can be reconfigured to support the selected interleavedMIMO communications service configurations. If the infrastructure of theDCS 300 is indicated as not being able to be changed, the possibleinterleaved MIMO communications service configurations presented willinvolve using the existing infrastructure of remote units 318(1)-318(X)and their locations, but with possible different physical layer1002(1)-1002(X) assignments for distribution of MIMO communicationsstreams to the remote units 318(1)-318(X). If the infrastructure of theDCS 300 is indicated as being able to be changed, the possibleinterleaved MIMO communications service configurations presented canalso involve changing (e.g., adding to) the number and/or locationremote units 318(1)-318(X) along with possible different physical layer1002(1)-1002(X) assignments for distribution of MIMO communicationsstreams to the remote units 318(1)-318(X).

In this regard, FIG. 13 is a flowchart illustrating an exemplary process1300 of configuring and/or re-configuring the DCS 300 in FIGS. 5A and 5Bto support interleaved MIMO communications services based on theexisting remote units 318(1)-318(X) deployed in the DCS 300 and theirinstalled locations to achieve a desired interleaved MIMO communicationsservices performance in the DCS 300. The process 1300 may be representedby software instructions resident in the DCS 300 and executed by the HEC362 as an example. The process 1300 is referenced below as beingexecuted by the HEC 362, but such could be executed by another circuitor other computer outside of the DCS 300. The process starts (block1302), such as by initiation by a technician or customer sending aninterleaved MIMO communications service configuration request to the HEC362. It is determined by the HEC 362 if interleaved MIMO communicationsare already deployed for the DCS 300 (block 1304). The HEC 362 can checkthe routing configuration 1004 (FIG. 10A) or other setting in the DCS300 for example to determine if interleaved MIMO communications arealready deployed for the DCS 300. If interleaved MIMO communications arealready deployed for the DCS 300, the customer or technician can benotified, such as through a display or by communicating such informationover the external interface 360 (FIG. 4B) to another system (block1306). The process then ends (block 1308).

With continuing reference to FIG. 13, if in block 1304, interleaved MIMOcommunications are not already deployed for the DCS 300, the HEC 362determines if configuring the DCS 300 to support interleaved MIMOcommunications should be for the infrastructure of existing remote units318(1)-318(X) as they exist and are deployed in the DCS 300, or ifredesigns to the number and/or location of the remote units318(1)-318(X) in the DCS 300 are possible (block 1310). For example, acustomer or technician may indicate this information via the externalinterface 360, such as from a keyboard input or touchscreen input on adisplay as examples. If the configuring of the DCS 300 to supportinterleaved MIMO communications should be for the infrastructure ofexisting remote units 318(1)-318(X) as they exist, the HEC 362 thenperforms an interleaved MIMO upgrade estimation to determine how thephysical layers 1002(1)-1002(X) can be assigned to the remote units318(1)-318(X) to support interleaved MIMO communications (block 1312). Asimulation software, which may be resident in the DCS 300, and isexecuted by the HEC 362 analyzes the existing performance of the DCS 300and provides one or more possible interleaved MIMO communicationsservice configurations based on the analyzed performance with noadditional remote unit 318(1)-318(X) and no changes to the existinglocations of the remote units 318(1)-318(X) (block 1314). The processthen obtains the requirements of one or more different interleaved MIMOcommunication services based on the analyzed performance of the DCS 300(block 1316). The different interleaved MIMO communications servicescould include 2×2 interleaved MIMO communications service, 4×4interleaved MIMO communications service, N×N interleaved MIMOcommunications services. The requirements, such as coverage areas,capacity, bill of materials (BOM) space requirements, benchmarkinformation along with other options such as CAPEX and OPEX savings, canbe determined to achieve each of the different interleaved MIMOcommunications services (block 1318). For example, a 2×2 MIMO RFperformance simulation using a given building model can estimate orpredict the percentage MIMO coverage possible in a building. As anexample, a BOM generation software tool can be employed to providedetails of the radio interface circuits 304 required, RDCs 354, 356 orphysical layers required and/or how to group communications services andon to what physical layers 1002(1)-1002(X). The HEC 362 for example mayexecute software instructions facilitates a step-by-step process forperforming such simulation, such as on a graphical user interface (GUI).For example, a BOM software tool can be configured to interface with adatabase that has associated costs per the BOM generated by the BOMgenerator software tool. The performance, BOM, space, and costrequirements can be generated for each option including the originaldesign. The options can be compared with the original design tounderstand the cost savings, performance gains, space requirements foreach option

The different interleaved MIMO communications services along with theirdetermined requirements could then be presented to the technician orcustomer, along with the associated costs and savings information todetermine if the technician or customer would like to enable a routingconfiguration 1004 to provide a desired interleaved MIMO communicationsservices (block 1320). If the customer or technician does not choose todeploy a presented interleaved MIMO communications service, the processends (block 1308). If however, the customer or technician does choose todeploy a presented interleaved MIMO communications service, the HEC 362determines the validity of the choice and guides the technician orcustomer through the deployment steps, to activate the appropriatesettings and files in the DCS 300 to update the routing configuration1004, and then notifies the customer or technician (block 1322).

With continuing reference to FIG. 13, if in block 1310, it is decidedthat the configuring of the DCS 300 to support interleaved MIMOcommunications can allow redesign and/or re-configuration of theexisting remote units 318(1)-318(X) as they exist, the HEC 362 thenperforms an interleaved MIMO upgrade estimation to determine how thephysical layers 1002(1)-1002(X) can be assigned to the remote units318(1)-318(X) to support interleaved MIMO communications (block 1324).If the configuring of the DCS 300 to support interleaved MIMOcommunications can allow for a redesign of infrastructure of the remoteunits 318(1)-318(X), the HEC 362 then performs an interleaved MIMOupgrade estimation to determine how the physical layers 1002(1)-1002(X)can be assigned to the remote units 318(1)-318(X) to support interleavedMIMO communications based on changes to locations of the remote units318(1)-318(X) to achieve the optimum antenna to antenna distance in theremote units 318(1)-318(X) (block 1326). A simulation software, whichmay be resident in the DCS 300, and is executed by the HEC 362 analyzesthe existing performance of the DCS 300 and provides one or morepossible interleaved MIMO communications service configurations based onthe analyzed performance with no additional remote unit 318(1)-318(X)and no changes to the existing locations of the remote units318(1)-318(X) (block 1326). The process then obtains the requirementsone or more different interleaved MIMO communications services based onthe analyzed performance of the DCS 300 (block 1328). The differentinterleaved MIMO communications services could include 2×2 interleavedMIMO communications service, 4×4 interleaved MIMO communicationsservice, N×N interleaved MIMO communications services. The requirements,such as coverage areas, capacity, BOM space requirements, benchmarkinformation along with other options such as CAPEX and OPEX savings, canbe determined to achieve each of the different interleaved MIMOcommunications services (block 1328). The different interleaved MIMOcommunications services along with their determined requirements couldthen be presented to the technician or customer, along with theassociated costs and savings information to determine if the technicianor customer would like to enable a routing configuration 1004 to providea desired interleaved MIMO communications service (block 1330). If thecustomer or technician does not choose to deploy a presented interleavedMIMO communication service, the process ends (block 1308). If however,the customer or technician does choose to deploy a presented interleavedMIMO communication service, the HEC 362 determines the validity of thechoice and guides the technician or customer through the deploymentsteps, to activate the appropriate profile settings and files in the DCS300 to update the routing configuration 1004, and then notifies thecustomer or technician (block 1322).

FIG. 14 is a flowchart illustrating an exemplary process 1400 ofconfiguring and/or re-configuring the DCS in FIGS. 5A and 5B to supportinterleaved MIMO communications services based on the existing remoteunits 318(1)-318(X) deployed in the DCS 300 and with repositioninginstalled locations of remote units 318(1)-318(X) and/or adding MIMOcommunications streams to achieve a desired interleaved MIMOcommunications services performance in the DCS 300. The process 1400 inFIG. 14 can be employed as the processes involved in blocks 1312-1318and 1324-1330 in FIG. 13. The process starts (block 1402), and theexisting remote unit 318(1)-318(X) design for providing SISOcommunications services is loaded into the DCS 300 to build a model ofthe DCS 300 using a RF simulation software program (block 1404). Forexample, the RF simulation software program could generate reports onexisting interleaved MIMO communications service, such as a “heat map”on required additional BIOM, costs, and performance improvements neededto achieve along with comparisons between the different interleaved MIMOcommunications services and SISO communications services and co-locatedor traditional MIMO communications services (block 1406). The user couldalso generate estimates on the required additional BOM, budget,performance and improvement metrics of MIMO cell bonding configurationoptions and compare such with alternative co-located MIMO communicationsservices implementations using the RF simulation software program orother means. The user can then use the RF simulation software program orother program to obtain characteristics of different interleaved MIMOcommunications services that could include obtaining one or moreperformance characteristics to provide 2×2 interleaved MIMOcommunications service, 4×4 interleaved MIMO communications service, N×Ninterleaved MIMO communications services by the RF simulation softwareprogram (block 1408). These requirements, such as coverage areas,capacity, BOM space requirements, benchmark information along with otheroptions such as CAPEX and OPEX savings, can be determined to achieveeach of the different interleaved MIMO communications services (block1408). The different interleaved MIMO communications services and theirperformance along with their determined requirements could then bepresented to the technician or customer, along with the associated costsand savings information to determine if the technician or customer wouldlike to enable a routing configuration 1004 to provide a desiredinterleaved MIMO communication service (block 1410). The validity of theselected MIMO communications service along with the ability of the DCS300 and remote units 318(1)-318(X) to achieve is then determined alongwith the necessary profiles, settings, and routing configuration 1004 toenable the selected interleaved MIMO communications service for a futuredeployment, if desired (block 1412). Optionally, on the user request,the user can interface with the RF simulation software program tonavigate through equipment installation steps, to enable the requestedMIMO cell bonding profile, validate the performance of selectedinterleaved MIMO communications against the estimated results andpresent the results, such as through a GUI or other display. The HEC 362then enables the selected interleaved MIMO communications service, andvalidates the performance against the estimated performance to presentthe result to the technician or user (block 1414), and the process ends(block 1416).

As discussed above, to provide options for supporting interleaved MIMOcommunication services in the DCS 300, an analysis of the configurationprofiles for the DCS 300 can be performed. However, an analysis of theconfiguration profiles for the DCS 300 does not necessarily mean thatthe communications performance of DCS 300 can exactly be determined. Itmay be desired to determine the actual communications performance of DCS300 as part of support configuration and reconfiguration of the DCS 300to support interleaved MIMO communications services.

In this regard, FIG. 15A is a schematic diagram of the DCS 300 in FIGS.SA and 5B with an additional central MIMO analysis circuit 1500 that canbe employed in the central unit 306 to determine the actual routing ofMIMO communications signals to the remote units 318(1)-318(X) in the DCS300. FIG. 15B is a schematic diagram of a remote unit 318 in the DCS 300in FIGS. 5A and 5B with an additional MIMO analysis circuit 1500 todetermine the actual routing of MIMO communications signals to theremote units 318 and the location of the remote unit 318 in the DCS 300.The MIMO analysis circuit 1500 can be deployed as a remote MIMO analysiscircuit in each remote unit 318(1)-318(X) in FIGS. 5A and 5B. As will bediscussed in more detail below, the MIMO analysis circuit 1500 allowsfor automatedly determining any MIMO cell bonding between the remoteunits 318(1)-318(X) to determine the communications services in effectin the DCS 300 for further analysis.

With reference to FIGS. 15A and 15B, the MIMO analysis circuit 1500includes a signal processing circuit 1504 that is configured to receivedownlink and uplink communications signals 308D, 308U from the centralunit 306. For example, the MIMO analysis circuit 1500 may couple to abackplane 1506 of a chassis 1508 in which the central unit 306, such asthe radio interface circuits 304(1)-304(12) are located, to receive thecommunications signals 308D, 308U distributed by and received by theradio interface circuits 304(1)-304(12). The MIMO analysis circuit 1500may include a downlink input interface 1510D to receive analog downlinkcommunications signals 308D and an uplink input interface 1510U toreceive analog uplink communications signals 308U. The MIMO analysiscircuit 1500 may also include a digital signal interface 1512 to receivedigital downlink and uplink communications signals 308D, 308U. The MIMOanalysis circuit 1500 in this example also includes one or more antennas1514 to be able to receive signals used to determine location of theMIMO analysis circuit 1500. For example, WiFi, satellite, and/orcellular communications signals may be used to determine the location ofthe MIMO analysis circuit 1500. The signal processing circuit 1504 canbe configured to use the reception of such signals from the antennas1514 to determine the location of the MIMO analysis circuit 1500. Thismay be particularly important for MIMO analysis circuit 1500 included ina remote unit 318, because part of the analysis and configuration ofcommunications services of the DCS 300 involves the location of theremote units 318(1)-318(X) and their relative distance from other remoteunits 318(1)-318(X) to determine possible interleaved MIMO cell bondingbetween the remote units 318(1)-318(X).

FIG. 16 is a schematic diagram of exemplary components that can beincluded in the MIMO analysis circuit 1500 in FIGS. 15A and 15B. Asillustrated in FIG. 16, the MIMO analysis circuit 1500 can include aseries of wireless receivers 1600(1)-1600(X) that are configured totransmit local wireless communications signals over respective antennas1514(1)-1514(X). As discussed above, the wireless receivers1600(1)-1600(X) can include a WiFi transmitter and/or Bluetoothtransmitter that are configured to receive wireless communicationssignals to be used to determine the location of the MIMO analysiscircuit 1500. The MIMO analysis circuit 1500 also includes the signalprocessing circuit 1504, which may be provided in the form of aprocessor, such as a digital signal processor (DSP), where applicationlayer applications reside and are executed. The application layerapplications can allow handling of functions of the MIMO analysiscircuit 1500, such as configuration, setting the identificationinformation, and control of reception of wireless communications signalsby communication through the communications interfaces 1602. Theapplication layer applications to be executed by the signal processingcircuit 1504 can be stored in internal memory 1604. The applicationlevel applications can also be stored in the internal memory 1604. TheMIMO analysis circuit 1500 can also include a power management module1606 to manage power consumption. The MIMO analysis circuit 1500 canalso include one or more physical communications ports 1608(1)-1608(Y)to receive the downlink and uplink communications signals 308D, 308U foranalyzing communications services. The MIMO analysis circuit 1500 mayalso include one or more external memory interfaces 1610(1)-1610(Z),such as memory card ports, USB ports, etc. for storing data frominternal memory 1604, including application level information. The MIMOanalysis circuit 1500 may also include one or more peripheral interfaceports 1612(1)-1612(A) for connecting other peripheral devices.

FIG. 17 is a flowchart illustrating an exemplary process 1700 ofautomatedly determining the actual routing of MIMO communicationssignals and locations of the remote units 318(1)-318(X) in the DCS 300and any MIMO cell bonding between the remote units 318(1)-318(X) todetermine the configured interleaved MIMO configuration in effect in theDCS 300. The DCS 300 can then be re-configured if desired to provide thedesired interleaved MIMO configuration in response to the determinedinterleaved MIMO configuration in the DCS 300. In this regard, theprocess 1700 starts (block 1702), and the HEC 362 in the DCS 300commands the MIMO analysis circuit 1500 in the central unit 306 toidentify and quantify the streams of communications signals 308D, 308U,including any MIMO communications streams of each radio interfacecircuit 304(1)-304(T) (block 1704). The DCS 300 is updated with thedetermined information. The DCS 300 then commands the MIMO analysiscircuits 1500 in the remote units 318(1)-318(X) to identify and quantifythe streams of communications signals 308D, 308U, including any MIMOcommunications streams of each remote unit 318(1)-318(X) and theneighboring, adjacent remote units 318(1)-318(X) (block 1706). Theinterference at each remote unit 318(1)-318(X) is also determined. TheDCS 300 is updated with the determined information. Based on theidentified and quantified information determined by the MIMO analysiscircuits 1500 at each remote unit 318(1)-318(X) and the radio interfacecircuits 304(1)-304(T), and the physical connection information based onthe routing configuration 1004, the HEC 362 maps the signal routingbetween each radio interface circuit 304(1)-304(T) and the remote units318(1)-318(X) (block 1708). The DCS 300 uses the location informationand the interference information from the MIMO analysis circuits 1500 inthe remote units 318(1)-318(X) to provision MIMO communications streamsin a routing configuration 1004 to achieve the interleaved MIMO cellbonding between remote units 318(1)-318(X) to achieve interleaved MIMOcommunications services (block 1710). The HEC 362 then determines if therouting configuration 1004 will provide for the interleaved MIMO cellbonding to not impact non-MIMO cell bonded remote units 318(1)-318(X) byensuring accurate routing (block 1712). The HEC 362 may thenperiodically check for changes in the environment and status to thenreadjust the routing of downlink communications signals 308D to achievethe desired interleaved MIMO cell bonding between remote units318(1)-318(X) to achieve interleaved MIMO communications services (block1714), and the process ends (block 1716).

FIG. 18 is a flowchart illustrating an exemplary process 1800 fordetermining the MIMO cell bonding in the DCS 300 to provide the desiredinterleaved MIMO configuration and communications services in the DCS300. The process 1800 in FIG. 18 can be employed in block 1710 in theprocess 1700 in FIG. 17. The process 1800 starts (block 1802) by the HEC362 determining if the DCS 300 has access to simulation software tosimulate the communications performance of the DCS 300 (block 1804). Ifso, the DCS 300 (e.g., HEC 362) uses the simulation software to optimizethe distance between the remote units 318(1)-318(X) horizontally andvertically to achieve the desired MIMO communications performance frominterleaved MIMO cell bonding (block 1806). The DCS 300 may use thesimulation software to optimize interleaved MIMO cell bondingperformance and present these performances versus their cost implicationto a customer or technician (block 1808). If the technician or customerdesires to employ one of the simulated options (block 1810), the DCS 300creates and saves the corresponding design information and routingconfiguration 1004 needed to deploy the chosen option and providescontact information to determine next steps for making physical changesto the DCS 300 (block 1812), and the process ends (block 1814). If thetechnician or customer does not desire to employ one of the simulatedoptions (block 1810), the DCS 300 discards corresponding designinformation and routing configuration 1004 needed to deploy the chosenoption (block 1816), and the process ends (block 1814).

If in block 1804, the HEC 362 determines that the DCS 300 does not haveaccess to simulation software to simulate the communications performanceof the DCS 300, the DCS 300 may alternatively use design rules tooptimize the distances among the remote units 318(1)-318(X) horizontallyand vertically to achieve the desired MIMO communications performancefrom interleaved MIMO cell bonding (block 1818). The DCS 300 may use thedesign rules to optimize interleaved MIMO cell bonding performance andpresent these performances versus their cost implication to a customeror technician (block 1820). If the technician or customer desires toemploy one of the design options (block 1810), the DCS 300 creates andsaves the corresponding design information and routing configuration1004 needed to deploy the chosen option and provides contact informationto determine next steps for making physical changes to the DCS 300(block 1812), and the process ends (block 1814). If the technician orcustomer does not desire to employ one of the simulated options (block1810), the DCS 300 discards corresponding design information and routingconfiguration 1004 needed to deploy the chosen option (block 1816), andthe process ends (block 1814).

FIGS. 19A and 19B are diagrams of exemplary graphical user interfaces(GUI) 1900, 1930 that facilitate configuring and/or reconfiguringdistribution of MIMO communications streams in a DCS, such as the DCS300 in FIGS. 5A and 5B and according to any of the exemplary interleavedMIMO communications services discussed herein. The HEC 362 for examplemay execute software instructions that generate the GUIs 1900, 1930 tobe displayed on a display in a computer system to a customer ortechnician in response to a processor executing of softwareinstructions. In this regard, as shown in FIG. 19A, the GUI 1900includes a main menu 1902 of options to manage the configuration andsettings of the DCS 300 to provide the desired communications services.For example, a user can select the CONFIG tab 1904 to review and editthe configuration settings for the DCS 300. The DCS 300 selected isshown in the DCS identification section 1905. A workstation mix area1906 is presented to the user that includes a floor plan layout of abuilding in which the DCS 300 is installed. Details of the existingrooms and planned rooms for the building in which the DCS 300 isinstalled as shown in building and planning areas 1908, 1910. Theadministration history of the DCS 300 is displayed in an administrationhistory area 1912. The module information on the modules in the DCS 300is shown in a modulation information area 1913 in response to selectionof the module information tab 1914. The RF presentation of the DCS 300to show a heat map of the DCS 300 can be initiated by selecting the RFpresentation tab 1916. The module configuration in the DCS 300 can bemodified by selecting the modify button 1918 and viewed by selecting theview button 1920.

FIG. 19B illustrates another GUI 1930 that is based on selected theprofiles tab 1932 in the main menu 1902. As discussed above, profilesstore configuration information for configuring the DCS 300 to providethe desired communications services. The central unit 306 configurationof the DCS 300 is shown in area 1936. The optical ports of the DCS 300for the selected optical interface circuit 310 are shown in area 1938,where optical port 1 1940(1) is shown as being configured. Optical ports2 and 3 can be added or removed by selecting the add remove buttons1941(2), 1941(3). A profile list 1946 of the DCS 300 is shown with thenames of profiles 1942 that can be configured for the DCS 300 to achievedifferent communications services. For a selected profile 1942 in theprofiles list 1946, profile options 1944 are provided for creating,importing profiles, including from third party software such as IBWavefor example. These profiles 1942 can be imported to configure the DCS300. A selected profile 1942 can also be modified by selecting a button1950 in a profile options window 1948. These modifications can includeediting, deleting, returning, saving, exporting, and activation of aselected profile 1942.

The software executed to perform the processes in FIGS. 17 and 18, andgenerate the GUIs 1900, 1930 in FIGS. 19A and 19B could be provided bythe RF simulation software program discussed in U.S. patent applicationSer. No. 15/332,603, entitled “Implementing A Live Wireless DistributionSystem (WDS) Configuration From A Virtual WDS Design Using An OriginalEquipment Manufacturer (OEM) Specific Software System In A WDS,” whichis incorporated by reference herein in its entirety.

FIG. 20 is a schematic diagram representation of additional detailillustrating a computer system 2000 that could be employed in anycomponent in the DCS 300 in FIGS. 15A and 15B, including but not limitedto the MIMO analysis circuit 1500 (FIGS. 15A-16) the routing circuit1000 (FIGS. 10A, 11A and 12), and the HEC 362 (FIG. 4B) to supportconfiguring and/or reconfiguring distribution of MIMO communicationsstreams to support interleaved MIMO communications services. Thecomputer system 2000 can be configured to support programming a routingconfiguration 1004, and/or to support providing GUI to a display, asshown in FIGS. 19A and 19B for example. In this regard, the computersystem 2000 is adapted to execute instructions from an exemplarycomputer-readable medium to perform these and/or any of the functions orprocessing described herein. The computer system 2000 may be connected(e.g., networked) to other machines in a LAN, an intranet, an extranet,or the Internet. While only a single device is illustrated, the term“device” shall also be taken to include any collection of devices thatindividually or jointly execute a set (or multiple sets) of instructionsto perform any one or more of the methodologies discussed herein. Thecomputer system 2000 may be a circuit or circuits included in anelectronic board card, such as, a printed circuit board (PCB), a server,a personal computer, a desktop computer, a laptop computer, a personaldigital assistant (PDA), a computing pad, a mobile device, or any otherdevice, and may represent, for example, a server or a user's computer.

The exemplary computer system 2000 in this embodiment includes aprocessing device or processor 2002, a main memory 2004 (e.g., read-onlymemory (ROM), flash memory, dynamic random access memory (DRAM), such assynchronous DRAM (SDRAM), etc.), and a static memory 2006 (e.g., flashmemory, static random access memory (SRAM), etc.), which may communicatewith each other via a data bus 2008. Alternatively, the processor 2002may be connected to the main memory 2004 and/or static memory 2006directly or via some other connectivity means. The processor 2002 may bea controller, and the main memory 2004 or static memory 2006 may be anytype of memory. For example, the routing configuration 1004 may bestored in the main memory 2004 and loaded into static memory 2006 whenbeing programmed, changed, or otherwise accessed, and then reloaded intomain memory 2004.

The processor 2002 represents one or more general-purpose processingdevices, such as a microprocessor, central processing unit, or the like.More particularly, the processor 2002 may be a complex instruction setcomputing (CISC) microprocessor, a reduced instruction set computing(RISC) microprocessor, a very long instruction word (VLIW)microprocessor, a processor implementing other instruction sets, orother processors implementing a combination of instruction sets. Theprocessor 2002 is configured to execute processing logic in instructionsfor performing the operations and steps discussed herein.

The computer system 2000 may further include a network interface device2010. The computer system 2000 also may or may not include an input2012, configured to receive input and selections to be communicated tothe computer system 2000 when executing instructions. The computersystem 2000 also may or may not include an output 2014, including butnot limited to a display, a video display unit (e.g., a liquid crystaldisplay (LCD) or a cathode ray tube (CRT)), an alphanumeric input device(e.g., a keyboard), and/or a cursor control device (e.g., a mouse).

The computer system 2000 may or may not include a data storage devicethat includes instructions 2016 stored in a computer-readable medium2018. The instructions 2016 may also reside, completely or at leastpartially, within the main memory 2004 and/or within the processor 2002during execution thereof by the computer system 2000, the main memory2004 and the processor 2002 also constituting computer-readable medium.The instructions 2016 may further be transmitted or received over anetwork 2020 via the network interface device 2010.

While the computer-readable medium 2018 is shown in an exemplaryembodiment to be a single medium, the term “computer-readable medium”should be taken to include a single medium or multiple media (e.g., acentralized or distributed database, and/or associated caches andservers) that store the one or more sets of instructions. The term“computer-readable medium” shall also be taken to include any mediumthat is capable of storing, encoding, or carrying a set of instructionsfor execution by the processing device and that cause the processingdevice to perform any one or more of the methodologies of theembodiments disclosed herein. The term “computer-readable medium” shallaccordingly be taken to include, but not be limited to, solid-statememories, optical medium, and magnetic medium.

The embodiments disclosed herein include various steps. The steps of theembodiments disclosed herein may be formed by hardware components or maybe embodied in machine-executable instructions, which may be used tocause a general-purpose or special-purpose processor programmed with theinstructions to perform the steps. Alternatively, the steps may beperformed by a combination of hardware and software.

The embodiments disclosed herein may be provided as a computer programproduct, or software, that may include a machine-readable medium (orcomputer-readable medium) having stored thereon instructions, which maybe used to program a computer system (or other electronic devices) toperform a process according to the embodiments disclosed herein. Amachine-readable medium includes any mechanism for storing ortransmitting information in a form readable by a machine (e.g., acomputer). For example, a machine-readable medium includes: amachine-readable storage medium (e.g., ROM, random access memory(“RAM”), a magnetic disk storage medium, an optical storage medium,flash memory devices, etc.); and the like.

Unless specifically stated otherwise and as apparent from the previousdiscussion, it is appreciated that throughout the description,discussions utilizing terms such as “processing,” “computing,”“determining,” “displaying,” or the like, refer to the action andprocesses of a computer system, or similar electronic computing device,that manipulates and transforms data and memories represented asphysical (electronic) quantities within the computer system's registersinto other data similarly represented as physical quantities within thecomputer system memories or registers or other such information storage,transmission, or display devices.

The algorithms and displays presented herein are not inherently relatedto any particular computer or other apparatus. Various systems may beused with programs in accordance with the teachings herein, or it mayprove convenient to construct more specialized apparatuses to performthe required method steps. The required structure for a variety of thesesystems will appear from the description above. In addition, theembodiments described herein are not described with reference to anyparticular programming language. It will be appreciated that a varietyof programming languages may be used to implement the teachings of theembodiments as described herein.

Those of skill in the art will further appreciate that the variousillustrative logical blocks, modules, circuits, and algorithms describedin connection with the embodiments disclosed herein may be implementedas electronic hardware, instructions stored in memory or in anothercomputer-readable medium and executed by a processor or other processingdevice, or combinations of both. The components of the distributedantenna systems described herein may be employed in any circuit,hardware component, integrated circuit (IC), or IC chip, as examples.Memory disclosed herein may be any type and size of memory and may beconfigured to store any type of information desired. To clearlyillustrate this interchangeability, various illustrative components,blocks, modules, circuits, and steps have been described above generallyin terms of their functionality. How such functionality is implementeddepends on the particular application, design choices, and/or designconstraints imposed on the overall system. Skilled artisans mayimplement the described functionality in varying ways for eachparticular application, but such implementation decisions should not beinterpreted as causing a departure from the scope of the presentembodiments.

The various illustrative logical blocks, modules, and circuits describedin connection with the embodiments disclosed herein may be implementedor performed with a processor, a Digital Signal Processor (DSP), anApplication Specific Integrated Circuit (ASIC), a Field ProgrammableGate Array (FPGA), or other programmable logic device, a discrete gateor transistor logic, discrete hardware components, or any combinationthereof designed to perform the functions described herein. Furthermore,a controller may be a processor. A processor may be a microprocessor,but in the alternative, the processor may be any conventional processor,controller, microcontroller, or state machine. A processor may also beimplemented as a combination of computing devices (e.g., a combinationof a DSP and a microprocessor, a plurality of microprocessors, one ormore microprocessors in conjunction with a DSP core, or any other suchconfiguration).

The embodiments disclosed herein may be embodied in hardware and ininstructions that are stored in hardware, and may reside, for example,in RAM, flash memory, ROM, Electrically Programmable ROM (EPROM),Electrically Erasable Programmable ROM (EEPROM), registers, a hard disk,a removable disk, a CD-ROM, or any other form of computer-readablemedium known in the art. An exemplary storage medium is coupled to theprocessor such that the processor can read information from, and writeinformation to, the storage medium. In the alternative, the storagemedium may be integral to the processor. The processor and the storagemedium may reside in an ASIC. The ASIC may reside in a remote station.In the alternative, the processor and the storage medium may reside asdiscrete components in a remote station, base station, or server.

It is also noted that the operational steps described in any of theexemplary embodiments herein are described to provide examples anddiscussion. The operations described may be performed in numerousdifferent sequences other than the illustrated sequences. Furthermore,operations described in a single operational step may actually beperformed in a number of different steps. Additionally, one or moreoperational steps discussed in the exemplary embodiments may becombined. Those of skill in the art will also understand thatinformation and signals may be represented using any of a variety oftechnologies and techniques. For example, data, instructions, commands,information, signals, bits, symbols, and chips, that may be referencesthroughout the above description, may be represented by voltages,currents, electromagnetic waves, magnetic fields, or particles, opticalfields or particles, or any combination thereof.

Unless otherwise expressly stated, it is in no way intended that anymethod set forth herein be construed as requiring that its steps beperformed in a specific order. Accordingly, where a method claim doesnot actually recite an order to be followed by its steps, or it is nototherwise specifically stated in the claims or descriptions that thesteps are to be limited to a specific order, it is in no way intendedthat any particular order be inferred.

It will be apparent to those skilled in the art that variousmodifications and variations can be made without departing from thespirit or scope of the invention. Since modifications, combinations,sub-combinations and variations of the disclosed embodimentsincorporating the spirit and substance of the invention may occur topersons skilled in the art, the invention should be construed to includeeverything within the scope of the appended claims and theirequivalents.

1. A distributed communications system (DCS), comprising: a central unitconfigured to: distribute received one or more downlink communicationssignals over one or more downlink communications links among a pluralityof downlink communications links to one or more remote units among aplurality of remote units according to a routing configuration; anddistribute received one or more uplink communications signals from theplurality of remote units over a plurality of uplink communicationslinks; and the central unit comprising: a routing configurationassigning the received one or more downlink communications signals toone or more remote units among the plurality of remote units; and acentral multiple-input, multiple-output (MIMO) analysis circuitconfigured to determine a presence of MIMO communications signals amongthe received one or more downlink communications signals; each remoteunit among the plurality of remote units comprising at least one antennaand configured to: distribute received uplink communications signalsreceived over the at least one antenna over an uplink communicationslink among the plurality of uplink communications links to the centralunit; and distribute received downlink communications signals from adownlink communications link among the plurality of downlinkcommunications links through the at least one antenna; each remote unitamong the plurality of remote units further comprising a remote MIMOanalysis circuit configured to: determine a presence of MIMOcommunications signals among the received downlink communicationssignals; determine location of the remote unit; and provide MIMOanalysis information comprising the presence of MIMO communicationssignals and the determined location of the remote unit; the central unitfurther comprising a controller configured to: instruct the central MIMOanalysis circuit to analyze the received one or more downlinkcommunications signals to determine the presence of MIMO communicationssignals; instruct the plurality of remote units to cause theirrespective remote MIMO analysis circuit to analyze the received one ormore downlink communications signals to determine the presence of MIMOcommunications signals; determine a routing configuration of thedetermined MIMO communications signals among the one or more downlinkcommunications signals from the central unit to the plurality of remoteunits; receive MIMO analysis information from each remote unit among theplurality of remote units indicating the determined presence of MIMOcommunications signals and the location of the remote unit; in responseto the determined presence of MIMO communications signals from thereceived MIMO analysis information; determine at least one interleavedMIMO configuration for the routing configuration based on the receivedMIMO analysis information; and configure the routing configuration basedon the determined at least one interleaved MIMO configuration: assign afirst MIMO communications signal among the received one or more downlinkcommunications signals for a first MIMO communications service to afirst remote unit among the plurality of remote units having a firstremote coverage area; and assign a second MIMO communications signalamong the received one or more downlink communications signals for thefirst MIMO communications service to a second remote unit among theplurality of remote units having a second remote coverage areaoverlapping with the first remote coverage area to interleave MIMO cellbond the first remote unit and the second remote unit.
 2. The DCS ofclaim 1, wherein the controller is further configured to determine anexisting performance of the plurality of remote units to provideinterleaved MIMO communications services based on the received MIMOanalysis information.
 3. The DCS of claim 2, wherein the controller isfurther configured to determine the existing performance of theplurality of remote units to provide interleaved MIMO communicationsservices by being configured to: simulate at least one interleaved MIMOcommunications service for the DCS based on the existing plurality ofremote units; and determine at least one performance characteristic ofthe simulated at least one interleaved MIMO communications service forthe DCS based on the existing plurality of remote units.
 4. The DCS ofclaim 1, wherein the controller is configured to instruct the pluralityof remote units to cause their respective remote MIMO analysis circuitto analyze their received one or more downlink communications signals todetermine the presence of MIMO communications signals by beingconfigured to: instruct each remote unit among the plurality of remoteunits to cause its respective remote MIMO analysis circuit to analyzethe received one or more downlink communications signals to determinethe presence of MIMO communications signals; and instruct each adjacentremote unit among the plurality of remote units to the remote unit tocause its respective remote MIMO analysis circuit to analyze thereceived one or more downlink communications signals to determine thepresence of MIMO communications signals.
 5. The DCS of claim 1, whereineach remote MIMO analysis circuit is further configured to: Determineradio frequency (RF) interference information; and provide the MIMOanalysis information comprising the presence of MIMO communicationssignals, and the determined location of the remote unit, and the RFinterference information.
 6. The DCS of claim 1, wherein in response tothe determined presence of MIMO communications signals from the receivedMIMO analysis information, the controller is further configured toconfigure the routing configuration based on distances between adjacentremote units among the plurality of remote units.
 7. The DCS of claim 1,wherein the controller is further configured to: send the determined atleast one interleaved MIMO configuration for the routing configurationover an external interface; receive an indication of an acceptance ofthe at least one interleaved MIMO configuration; and configure therouting configuration based on the determined at least one interleavedMIMO configuration based on the received indication of the acceptance ofthe at least one interleaved MIMO configuration.
 8. The DCS of claim 1,wherein: the central MIMO analysis circuit is further configured todetermine a presence of MIMO communications signals among the receivedone or more uplink communications signals; the remote MIMO analysiscircuit in each remote unit among the plurality of remote units isconfigured to determine the presence of MIMO communications signalsamong the received uplink communications signals; and the controller isfurther configured to: instruct the central MIMO analysis circuit toanalyze the received one or more uplink communications signals todetermine the presence of MIMO communications signals; instruct theplurality of remote units to cause their respective remote MIMO analysiscircuit to analyze the received one or more uplink communicationssignals to determine the presence of MIMO communications signals;determine a routing configuration of the determined MIMO communicationssignals among the one or more uplink communications signals from thecentral unit to the plurality of remote units.
 9. The DCS of claim 1,wherein the controller is further configured to configure the routingconfiguration based on the determined at least one interleaved MIMOconfiguration to: assign a third MIMO communications signal among thereceived one or more downlink communications signals for the first MIMOcommunications service to a third remote unit among the plurality ofremote units having a third remote coverage area overlapping with thefirst remote coverage area and the second remote coverage area tointerleave MIMO cell bond the third remote unit to the first remote unitand the second remote unit; and assign a fourth MIMO communicationssignal among the received one or more downlink communications signalsfor the first MIMO communications service to a fourth remote unit amongthe plurality of remote units having a fourth remote coverage areaoverlapping with the first remote coverage area, the second remotecoverage area, and the third remote coverage area to interleave MIMOcell bond the fourth remote unit to the first remote unit, the secondremote unit, and the third remote unit.
 10. The DCS of claim 1, whereinthe controller is further configured to configure the routingconfiguration based on the determined at least one interleaved MIMOconfiguration to: assign a third MIMO communications signal among thereceived one or more downlink communications signals for a second MIMOcommunications service to a third remote unit among the plurality ofremote units having a third remote coverage area; and assign a fourthMIMO communications signal among the received one or more downlinkcommunications signals for the second MIMO communications service to afourth remote unit among the plurality of remote units having a fourthremote coverage area overlapping with the third remote coverage area tointerleave MIMO cell bond the third remote unit and the fourth remoteunit.
 11. The DCS of claim 10, wherein the controller is furtherconfigured to configure the routing configuration based on thedetermined at least one interleaved MIMO configuration to: assign afifth MIMO communications signal among the received one or more downlinkcommunications signals for the second MIMO communications service to afifth remote unit among the plurality of remote units having a fifthremote coverage area; and assign a sixth MIMO communications signalamong the received one or more downlink communications signals for thesecond MIMO communications service to a sixth remote unit among theplurality of remote units having a sixth remote coverage areaoverlapping with the fifth remote coverage area to interleave MIMO cellbond the fifth remote unit and the sixth remote unit.
 12. The DCS ofclaim 1, wherein the controller is further configured to configure therouting configuration based on the determined at least one interleavedMIMO configuration to: split the first MIMO communications signal intoat least two first split MIMO communications signals; split the secondMIMO communications signal into at least two second split MIMOcommunications signals; the central unit configured to configure therouting configuration to: assign a first split MIMO communicationssignal of the at least two first split MIMO communications signals forthe first MIMO communications service to the first remote unit among theplurality of remote units having the first remote coverage area; andassign a second split MIMO communications signal of the at least twofirst split MIMO communications signals for the first MIMOcommunications service to the second remote unit among the plurality ofremote units having the second remote coverage area overlapping with thefirst remote coverage area to interleave MIMO cell bond the first remoteunit and the second remote unit; assign a first split MIMOcommunications signal of they at least two second split MIMOcommunications signals for the first MIMO communications service to athird remote unit among the plurality of remote units having a thirdremote coverage area; and assign a second split MIMO communicationssignal of the at least two second split MIMO communications signals forthe first MIMO communications service to a fourth remote unit among theplurality of remote units having a fourth remote coverage areaoverlapping with the third remote coverage area to interleave MIMO cellbond the third remote unit and the fourth remote unit.
 13. The DCS ofclaim 1, wherein the central unit comprises at least one MIMO splittercircuit configured to: split the first MIMO communications signal intoat least two first split MIMO communications signals.
 14. The DCS ofclaim 1, wherein the plurality of downlink communications links and theplurality of uplink communications links are the same respectivecommunications links.
 15. The DCS of claim 1, wherein the first remoteunit is located within at least 20 meters of the second remote unit. 16.The DCS of claim 1, wherein the first remote unit is located within atleast 12 meters of the second remote unit.
 17. (canceled)
 18. A methodof configuring a distributed communications systems (DCS) for providinginterleaved multiple-input, multiple-output (MIMO) communicationsservices, comprising: instructing a central MIMO analysis circuit in acentral unit of the DCS to analyze received at least one downlinkcommunications signals to determine a presence of MIMO communicationssignals, the DCS comprising: the central unit configured to: distributereceived one or more downlink communications signals over one or moredownlink communications links among a plurality of downlinkcommunications links to one or more remote units among a plurality ofremote units according to a routing configuration; and distributereceived one or more uplink communications signals from the plurality ofremote units over a plurality of uplink communications links; and thecentral unit comprising: a routing configuration assigning the receivedone or more downlink communications signals to one or more remote unitsamong the plurality of remote units; and a central MIMO analysis circuitconfigured to determine the presence of MIMO communications signalsamong the received one or more downlink communications signals; eachremote unit among the plurality of remote units comprising at least oneantenna and configured to: distribute received uplink communicationssignals over the at least one antenna over an uplink communications linkamong the plurality of uplink communications links to the central, unit;and distribute received downlink communications signals from a downlinkcommunications link among the plurality of downlink communications linksthrough the at least one antenna; each remote unit among the pluralityof remote units further comprising a remote MIMO analysis circuitconfigured to: determine the presence of MIMO communications signalsamong the received downlink communications signals; determine locationof the remote unit; and provide MIMO analysis information comprising thepresence of MIMO communications signals and the determined location ofthe remote unit; instructing the plurality of remote units to causetheir respective remote MIMO analysis circuit to analyze the receivedone or more downlink communications signals to determine the presence ofMIMO communications signals; determining a routing configuration of thedetermined MIMO communications signals among the received one or moredownlink communications signals from the central unit to the pluralityof remote units; receiving MIMO analysis information from each remoteunit among the plurality of remote units indicating the determinedpresence of MIMO communications signals and the location of the remoteunit; in response to the determined presence of MIMO communicationssignals from the received MIMO analysis information; determining atleast one interleaved MIMO configuration for the routing configurationbased on the received MIMO analysis information; and configuring therouting configuration based on the determined at least one interleavedMIMO configuration by: assigning a first MIMO communications signalamong the received one or more downlink communications signals for afirst MIMO communications service to a first remote unit among theplurality of remote units having, a first remote coverage area; andassigning a second MIMO communications signal among the received one ormore downlink communications signals for the first MIMO communicationsservice to a second remote unit among the plurality of remote unitshaving a second remote coverage area overlapping with the first remotecoverage area to interleave MIMO cell bond the first remote unit and thesecond remote unit.
 19. The method of claim 18, further comprisingdetermining an existing performance of the plurality of remote units toprovide interleaved MIMO communications services based on the receivedMIMO analysis information.
 20. The method of claim 19, furthercomprising determining the existing performance of the plurality ofremote units to provide interleaved MIMO communications services by:simulating at least one interleaved MIMO communications service for theDCS based on the existing plurality of remote units; and determining atleast one performance characteristic of the simulated at least oneinterleaved MIMO communications service for the DCS based on theexisting plurality of remote units.
 21. The method of claim 18,comprising instructing the plurality of remote units to cause theirrespective remote MIMO analysis circuit to analyze the received one ormore downlink communications signals to determine the presence of MIMOcommunications signals by: instructing each remote unit among theplurality of remote units to cause its respective remote MIMO analysiscircuit to analyze the received one or more downlink communicationssignals to determine the presence of MIMO communications signals; andinstructing each adjacent remote unit among the plurality of remoteunits to the remote unit to cause its respective remote MIMO analysiscircuit to analyze the received one or more downlink communicationssignals to determine the presence of MIMO communications signals. 22.The method of claim 18, further comprising each remote MIMO analysiscircuit configured to: determine radio frequency (RF) interferenceinformation; and provide the MIMO analysis information comprising thepresence of MIMO communications signals, and the determined location ofthe remote unit, and the RF interference information.
 23. The method ofclaim 18, wherein in response to the determined presence of MIMOcommunications signals from the received MIMO analysis information,configuring the routing configuration based on distances betweenadjacent remote units among the plurality of remote units.
 24. Themethod of claim 18, further comprising: sending the determined at leastone interleaved MIMO configuration for the routing configuration over anexternal interface; receiving an indication of an acceptance of the atleast one interleaved MIMO configuration; and configuring the routingconfiguration based on the determined at least one interleaved MIMOconfiguration based on the received indication of the acceptance of theat least one interleaved MIMO configuration.
 25. (canceled)